Which sentence from the passage most strongly communicates the central idea?
A. "People who turned toward their partners in the study responded by engaging the bidder, showing interest and support in the bid."
B. "Sometimes they would respond with overt hostility, saying something like, "Stop interrupting me, I'm reading."
C. "These bidding interactions had profound effects on marital well-being."
D. "Nine times out of ten, they were meeting their partner's emotional needs."