QUES:
Who is they in the following sentence?

UPS provides much convenience to the customers with their drop off service since they make the shipping of packages extremely easy.

OPTIONS:
- UPS
- the customers

ANS:
UPS

QUES:
Who is it in the following sentence?

The boulder dropped into the river, but it continued to roll.

OPTIONS:
- The boulder
- the river

ANS:
The boulder

QUES:
Who is they in the following sentence?

The Union defeated the Confederates in the Civil war since they did not have the resources to continue the fight.

OPTIONS:
- The Union
- the Confederates

ANS:
the Confederates