Final answer:
The nurse should suggest sexual positions that might be more comfortable for the couple experiencing dyspareunia during pregnancy.
Step-by-step explanation:
Out of the options provided, the best action for the nurse to take when a couple complains of dyspareunia during pregnancy is to suggest sexual positions that might be more comfortable (Option D). Dyspareunia is the term used to describe painful intercourse, and it is not a normal finding during pregnancy. By suggesting sexual positions that may alleviate discomfort, the nurse can help the couple continue to engage in sexual activity if they desire.