Which of the Following Is an Empirically Documented Result That

Which of the following is an empirically documented result that indicates that men adjust their behavior based on the quality of the target?

A) Men tip waitresses most if they are taller and brunette.
B) Men's skin conductance fluctuates less from baseline when speaking with an attractive woman.
C) Men increase the pitch of their voice when talking to an attractive woman.
D) The younger the woman,the more money the man spends on his engagement ring for her.