Advocates, contends, points out, and states are all examples of?
a. plagiarism
b. signal phrase attributions
c. citations
d. verbs

B. Signal phrase attributions.

Explanation:

The words given here display signal phrase attributions as it ascribes the quality of something or acts as an attribute to a particular literary work. Attribution regards the causes of actions. Thus, the words 'advocates', 'contends', 'points out' and 'states' exemplify the attributions as they symbolize the act of ascribing a work and its central concerns.

well for some you have to do on your own on a paper but yeah

mark twain, real name samuel langhorne clemens, was an american writer, humorist, entrepreneur, publisher, and lecturer. among his novels are the adventures of tom sawyer and its sequel, the adventures of huckleberry finn, the latter often called "the great american novel". wikipedia