Question

Be careful or you'll hurt ____! a. yourself b. yourselves c. either could be used

Answer 1

C is correct, because either A or B can be used, depending on the person or persons being addressed. If the speaker is addressing gone person, then the speaker would say "Be careful or you'll her yourself!" If the speaker is addressing two or more people, then the speaker would say "Be careful or you'll hurt yourselves!"

Answer 2

Either would work, so c. either could be used.