which pronoun best completes the sentence?
"the visitor took muddy boots off at the door."
a.
he

b.
his or her

c.
their

d.
its

The answer would be his or her, B. 
This is because if you go through each one and say it out loud that is the only one that sounds right. Also we are talking about the present not the past, which would be, he A. 

I'm not going to make it tonight and