Comprises or is comprised of?

Which is correct?
Data management is a broad area of study that ___________ many more specialized fields.
a. comprises
b. is comprised of

Answer: a

Explanation:
To comprise means to contain. Data management comprises many more specialized areas of study.

For Grammar Girl, Bonnie Trenga explains how to use comprise properly. Here’s an excerpt:

It seems simple enough: “to comprise” means “to contain” (1), as in “The house comprises seven rooms.” In other words, this house has or contains seven rooms. When you use “comprise,” you’re talking about all the parts that make up something. Usually. More on that a little later.

The important thing to remember when you’re using the word “comprise” is that the item that is the whole shebang comes first in the sentence; second come the items that are its parts. For example, you might say, “A full pack comprises 52 cards.” The pack is the whole shebang, so it comes first in the sentence. It would be wrong to say, “Fifty-two cards comprise a full pack.” Likewise, America comprises 50 states, not fifty states comprise America. In this sentence, America is the whole shebang, so it comes first in the sentence. The whole comprises the parts.

Trenga goes on to comment that fewer people in an editorial panel disapprove of the phrase “is comprised of” than was the case years ago:

The American Heritage Guide to Contemporary Usage and Style (6), however, has noticed an interesting trend. In 1965, 54% of the usage panel disapproved of the phrase “is comprised of,” whereas in 2005, 65% approved, which I take to mean that only 35% disapproved. As with a number of constructions we’ve discussed here on the “Grammar Girl” podcast, they say “the traditional distinction may be destined to fall by the wayside.” This guide does suggest that you observe the traditional rule though.

“Is comprised of” is still considered incorrect by a fairly large number of sources. So use “comprises” instead and no one can object.