D) getting your hair cut to a short, safe length
A gerund is a verb that is used as a noun. The gerund ends with /-ing/. In this sentence, the gerund is "getting". The gerund phrase is "getting your hair cut to a short, safe length".
A direct object is the recipient of the main verb's action. A direct object only comes after an action verb and never after a linking verb. Often it answers the question SUBJECT - VERB What? So...the job requires what? "Getting your hair...."
In the sentence, the job is the subject of the sentence. The rest of the options are all part of the gerund phrase.