To answer this question, we need to understand the concept of verb tenses and their usage.
The sentence is in the present tense and indicates an ongoing action. The correct option is:
Option B) is being used - This option is correct because it uses the present continuous tense to indicate that the room is currently being used for a meeting. The present continuous tense is formed by using "is/are + present participle (-ing)".
Let's analyze the other options:
Option A) is used - This option uses the simple present tense, which describes a habitual or general action. It does not convey the ongoing nature of the action required in the sentence.
Option C) used - This option uses the past tense, which is not appropriate in this context since the sentence refers to a current meeting.
Option D) is using - This option uses the present continuous tense, but it is incorrect because the subject "room" cannot actively "use" itself.
Therefore, the correct answer is Option B) is being used.