I think the second choice is most important
Fifty cents is a plural noun since it is talking about more than one cent. In the example, you would say, "fifty cents <em>is </em>how much I owe you".
Answer:
A. Last week Mark started <u>coming home late</u>, <u>missing classes</u>, and <u>arguing with his parents</u>
Explanation:
A parallel structure is used when the same pattern is repeated and the same pattern has the same function. For example, in the statement above, the verb <em>to start</em> is used with some complements. The complements , which refer to different activities, are expressed through participles ( _ing): <em>starting...; missing </em>...and <em>arguing.</em>.... These are all participles and function as the complement of <em>to start.</em>