Which of the italicized parts functions as a complement(补语)?

题目
单选题
Which of the italicized parts functions as a complement(补语)?
A

We were greatly encouraged by the news of China’s having launched another man-made satellite.

B

His wish is everyone’s having a good time.

C

I saw an old man getting on the bus.

D

The smiling boy needs a pen bought by his mother