Explanation:
The poet has followed the rhyming scheme abcbdd in all the stanzas except the second one. So the last one on your list.
The correct answer is D. Subject
The subject is the person/thing that does the action. In his case, it contains something which makes it the doer of the action of containing.
It can mean many things to certain people. However I feel like it means don’t let other people tell you your future instead follow “God”.