America . . . . . . the powerful president.

Answer: Option B

The correct answer is B: has

This question tests your understanding of subject-verb agreement.

Subject-verb agreement means that the verb in a sentence must agree in number (singular or plural) with its subject. The subject is the person, place, thing, or idea that the sentence is about.

In this sentence, the subject is "America," which is a singular proper noun (the name of a country).

The verb "has" is the singular form of the verb "to have." Therefore, "America has the powerful president" is grammatically correct because the singular subject "America" is paired with the singular verb "has."

Let's look at why the other options are incorrect:

A: have is the plural form of the verb "to have," and it doesn't agree with the singular subject "America."

C: is is the singular form of the verb "to be," but it doesn't fit the meaning of the sentence. The sentence is about possession ("has"), not being ("is").

D: does is the singular form of the auxiliary verb "to do," but it also doesn't fit the meaning of the sentence. We need a verb that indicates possession.