A recent study examining the causes of rising healthcare costs in the

This question is pretty interesting. Before we head over to the prompt, let us try to recall the significance of the present perfect tense.

The present perfect tense is used to indicate (or talk about) an event that has occurred in the past and whose effect is still felt today.

With this understanding, we can safely say that it wouldn't make much sense for the act of suggestion to start in the past and continue to exert its effect in the present. Hence, the usage of present perfect tense for 'suggestion' put forth by "recent study" is incorrect.

For this reason, we can eliminate C & E straight away.

Since the subject of the sentence is "A study", which is singular, the verb describing the subject must also be singular. In (A), the plural form 'suggest' is used. Hence, eliminate (A).

Now, we are left with A and D.

Here, we have to pay close attention to the meaning.

In A, the subject of the subordinate clause is 'increased utilization', which is singular. Hence, the verb that describes this subject must also be singular. But in A, the verb is 'are', which indicates pluralism. Hence, A is incorrect.

Therefore, D is the best answer choice.