It depends on the connotation of the word.
a. mentor- helps you shape your future
b. dictator- negative connotation, too controlling
c. leader- guidance
d.teacher- fills your knowledge
I WOULD SAY C. LEADER
The sentence the contains a compound subject is, option C. The Senate and the House of Representatives are part of the legislative branch. As you see, the subject of the sentence is more than one: The Senate and the House of Representatives. If there is more than one subject, it is called a compound subject.