How can you do this?

You had a contractor come into your company. You originally set his account to expire after thirty days. You now need to change this. How can you do this?

A.
usermod -e

B.
usermod -a

C.
usermod -x

D.
usermod -d

Explanation:
useradd [-c comment] [-d home_dir]

[-e expire_date] [-f inactive_time]
[-g initial_group] [-G group[,…]]
[-m [-k skeleton_dir] | -M] [-n] [-o] [-p passwd] [-r]
[-s shell] [-u uid] login