Final answer:
The initial intervention in the client's plan of care would be providing a dark, quiet room with minimal stimuli.
Step-by-step explanation:
The initial intervention in the client's plan of care would be B) Providing a dark, quiet room with minimal stimuli.
This intervention is appropriate because the client's symptoms, including weight gain and increased blood pressure, suggest the possibility of pre-eclampsia, a condition characterized by high blood pressure and organ damage. Providing a dark, quiet room with minimal stimuli helps to promote relaxation and reduce stress, which can help lower blood pressure.
Other interventions may be necessary depending on the severity of the client's condition, but initially, creating a calming environment is important.