Tom used to be afraid of speaking in front of many people. Now he's become much________ .

A. more generous

B. more honest

C. shier

D. more confident

D

句意：汤姆过去害怕在很多人面前讲话。现在他变得更加自信了。A. more generous更慷慨；B. more honest更诚实；C. shier更害羞；D. more confident更自信。结合语境理解，前句提到汤姆过去害怕在很多人面前讲话，显得不自信，后一句说明这种状况发生了改变，汤姆变得更加自信起来，答案为D。