Therapeutic management of most children with Hirschsprung's disease is primarily

The correct answer is choice C: Concrete operations stage.

Choice A rationale:

The preoperational stage, which occurs roughly between ages 2 and 7, is characterized by egocentrism, animism, and a lack of conservation. Children in this stage struggle with understanding that quantities can remain the same even if their appearance changes. For instance, they might think that pouring water from a tall glass into a short, wide glass somehow changes the amount of water. This stage does not demonstrate the mental understanding required for the examples given in the question.

Choice B rationale:

The intuitive thought stage, which typically spans from ages 4 to 7, is marked by increased symbolic thinking but still lacks the capacity for logical and systematic reasoning. Children in this stage might be able to count and perform basic arithmetic, but they struggle with more complex operations and understanding the underlying principles of mathematical operations. This stage is not where the ability to understand the given math operations is firmly established.

Choice C rationale:

The concrete operations stage, which encompasses ages 7 to 11, is characterized by the development of logical and systematic thinking. Children in this stage are capable of understanding basic mathematical principles and operations, such as conservation of quantity and simple arithmetic. They can mentally manipulate numbers and understand that reversing an operation will yield the original quantity. Therefore, this stage is when the ability to understand that 1 + 3 = 4 and 4 - 3 = 1 occurs.

Choice D rationale:

The formal operations stage, typically beginning around age 11, is characterized by abstract and hypothetical thinking. This is when adolescents and adults can engage in complex reasoning and consider multiple possibilities and outcomes. The given math operations are not the focus of this stage; rather, it pertains to more advanced cognitive abilities like hypothetical problem-solving and deductive reasoning.

The correct answer is choice C. Asthma.

Choice A rationale:

A foreign body in the trachea can cause acute respiratory distress and a sudden cough, but it is unlikely to cause chronic nonproductive cough and diffuse wheezing during the expiratory phase of respiration. The symptoms in the scenario are more suggestive of a chronic condition.

Choice B rationale:

Bronchiolitis primarily affects infants and young children, causing symptoms such as fever, rhinorrhea, and wheezing. While wheezing can be present, the diffuse wheezing during the expiratory phase described in the scenario is more characteristic of asthma.

Choice C rationale:

Asthma is characterized by chronic inflammation of the airways, leading to episodes of bronchoconstriction and increased airway reactivity. The chronic, nonproductive cough and diffuse wheezing during the expiratory phase are classic signs of asthma. Expiratory phase wheezing occurs due to the narrowing of the smaller airways during expiration.

Choice D rationale:

Pneumonia is an infection of the lung tissue and can cause productive cough, fever, and crackles on auscultation. While wheezing might occur in pneumonia due to inflammation and narrowing of the airways, it's not the most likely cause of the symptoms described in the scenario.