Three of the following statements about a verb are true. Which statement is false?

A. A verb takes the place of adjectives.

B. A verb can express a state of being.

C. A verb can express action.

D. A verb makes a statement about the subject of a sentence.

The false statement is the first one: an adjective gives some information about the noun, but not an action of the entity that the noun expresses.

The other options actions are correct. This is shown by the fact that "exists" satisfies options B, "runs" option C and "runs" in "girl runs" option D.