b. "Everyone who lives in the home will need medication."

The nurse should inform the guardian that everyone who lives in the home will need medication when reinforcing teaching about enterobiasis. Enterobiasis, also known as pinworm infection, is highly contagious, and it can easily spread from person to person within the household. Treating only the affected individual may not be sufficient to eliminate the infection completely, as other household members may also be infected or at risk of reinfection.

Explanation for the other options:

a. "One dose of medication is all that will be necessary." Enterobiasis is typically treated with a medication regimen that involves taking multiple doses over a period of time. This is to ensure that all stages of the pinworm life cycle are targeted and eradicated. A single dose is usually not sufficient to eliminate the infection completely.

c. "Allow the child to take tub baths instead of showers." The choice of tub baths or showers does not directly impact the treatment or prevention of enterobiasis. Both methods of bathing can be used, but it is important to maintain good hygiene practices, such as regular handwashing and proper cleaning of the perianal area, to reduce the risk of reinfection.

d. "Wash all clothes and bed linens in cold water." While proper hygiene practices and laundering of clothes and bed linens are important in preventing the spread of enterobiasis, using cold water alone may not be sufficient. Washing clothes and bed linens in hot water (at a temperature of at least 60°C or 140°F) is recommended to kill any pinworm eggs that may be present.

Placenta previa is a condition where the placenta partially or completely covers the opening of the cervix. One of the hallmark signs of placenta previa is painless vaginal bleeding, typically bright red in color. This bleeding can occur spontaneously or during activities that put pressure on the uterus, such as sexual intercourse or physical exertion.

A rigid abdomen is not typically associated with placenta previa. It may indicate other conditions, such as peritonitis or abdominal muscle rigidity, but it is not a characteristic finding of placenta previa.

Persistent uterine contractions are not typically associated with placenta previa. Placenta previa is more commonly associated with painless bleeding rather than contractions. However, if placenta previa is complicated by other factors, such as placental abruption, contractions and abdominal pain may be present.

Fetal movement is not directly related to placenta previa. Fetal movement can vary from person to person and does not specifically indicate placenta previa. However, it is important for the nurse to assess fetal well-being in clients with placenta previa as bleeding can impact the oxygen supply to the fetus.