The correct answer is A. simple subject.
Subject is a word, phrase, or even a clause, that does the action within a sentence, or experiences some sort of state. There are different types of subjects:
1. simple subject - consists of one word only; in the sentence above, the subject is the word <em>Melinda</em>
2. complete subject - contains all words connected to the simple subject; if the underlined part of the sentence was <em>Melinda, a college student from Maine, </em>then it would be a complete, rather than a simple subject
3. compound subject - contains more than one subject, connected with the conjunction <em>and; </em>for example, <em>Melinda and Bob</em>