Why is it important to fill out an interest inventory before searching for a job?
a-to make sure that you are qualified for the job that you choose
b-to practice filling out a form before you have to fill out job applications
c-to identify your strengths and preferences that you will take to a job

the pronoun reference replaces a noun, but you have to make sure there's no room for confusion.

in the first sentence "her" could be referring to shely or to the sister. the answer there is "shelly called her sister and told her about the new baby."

in the second sentence "it" could be referring to the roof or the floor. the answer there is "since the roof leaks on the family room floor, we need to repair the roof."