OG1 阅读 Q18

Choice D is the best answer. Lines 53-55("Perhaps ...onsideration.") state that "Perhaps givers believe that bigger (i.e., more expensive) gifts convey stronger signals of thoughtfulness and consideration." In this context, saying that more expensive gifts "convey" stronger signals means the gifts send, or communicate, stronger signals to the recipients.
Choices A, B, and C are incorrect because in this context, to "convey" something does not mean to transport it (physically move something), counteract it (act in opposition to something), or exchange it (trade one thing for another).