Question

A stop–payment request is _____.

a request to close a checking account
a request by an account holder for the bank to not pay a specific payment
a request to pay a bill electronically
request to stop a bill from being sent

Answer 1

A stop payment is a request made to a financial institution to cancel a check or a payment that has not been processed yet. 
So looking at your options it would be "A request to stop a bill from being sent"

Answer 2

the answer is request to stop a bill from being sent