Questions: Vitamins by the human body in many different ways. are easily using used easily use easily are easily used

The answer is D: are easily used.

Explanation for each option:

A. "are easily using" - This option is incorrect because "using" is a present participle and does not fit grammatically in this context. The sentence requires a past participle to form the passive voice.

B. "used easily" - This option is incorrect because it lacks the auxiliary verb "are," which is necessary to form the passive voice in the present tense.

C. "use easily" - This option is incorrect because it suggests that vitamins themselves are performing the action of using, which is not the intended meaning. The sentence should convey that vitamins are being used by the human body.

D. "are easily used" - This is the correct option because it uses the passive voice to indicate that vitamins are the object being used by the human body. The structure "are used" is appropriate for the present tense, and "easily" correctly modifies the verb phrase.