IN:
Multi-choice problem: [he]

John remembered Bill because he was memorable.

OUT:
Bill

IN:
Multi-choice problem: [he]

Joe tried to get Tom to wake up, but he couldn't.

OUT:
Joe

IN:
Multi-choice problem: [they]

The police called headquarters for help and they continued to fight the criminals.

OUT:
The police

IN:
Multi-choice problem: [he]

Cartman wanted Kenny to go to the same school as him, but he refused.

OUT:
Kenny