The correct answer and explanation is:

c. Denial

The nurse should identify that the client is experiencing the stage of denial in the grief process. Denial is a common psychological defense mechanism that individuals may exhibit when faced with a stressful or overwhelming situation, such as the prospect of open heart surgery. It involves a refusal to accept or acknowledge the reality of the situation. In this case, the client's statement of being confident to go home shortly after surgery demonstrates a denial of the potential challenges and recovery process associated with such a procedure.

Explanation for the other options:

A . Anger: Anger is a stage of grief characterized by feelings of resentment, frustration, and hostility. It is common for individuals to experience anger as part of the grief process, but the client's statement does not indicate anger.

B. Depression: Depression is another stage of grief marked by feelings of sadness, hopelessness, and loss. While it is normal for individuals to experience some level of anxiety or sadness before undergoing surgery, the client's statement does not specifically reflect depression.

d. Acceptance: Acceptance is the final stage of grief, where individuals come to terms with their situation and find a sense of peace or resolution. The client's statement indicates a lack of acceptance as they are denying the potential impact of the surgery and its recovery process.

Keeping a baby rear-facing in the car seat until they reach the age of 2 years old or until they reach the maximum height and weight limits recommended by the car seat manufacturer is a crucial safety guideline. Rear-facing car seats provide better support for a baby's head, neck, and spine in the event of a crash, reducing the risk of severe injuries.

"I should place my baby in the car seat at a 90-degree angle." The correct positioning for a rear-facing car seat is typically between a 30 to 45-degree angle. This angle helps ensure the baby's airway remains open and prevents their head from flopping forward.

"I should position the car seat's retainer clip at the level of my baby's belly button." The retainer clip of the car seat should be positioned at armpit level, not at the level of the baby's belly button. The retainer clip is designed to secure the harness straps and should be placed across the chest, resting on the bony part of the shoulders.

"I should enable the airbag when my baby is in the front seat of the car." It is not safe to have a rear-facing car seat with a baby in the front seat of a vehicle with an active airbag. Airbags can pose a significant risk to infants due to the force with which they deploy. It is recommended to place a rear-facing car seat in the back seat of the vehicle and disable the airbag in the front passenger seat if the baby needs to ride in the front.

It is important for parents to receive proper education on car seat safety and follow the guidelines set forth by car seat manufacturers, national recommendations, and local laws and regulations.