Could you tell me what time _____?

Auxiliary verb (could) + subject (you) +verb (tell) + question word (what) + subject (it) + verb (is).
Could you tell me what time it is? এর অর্থ এখন কয়টা বাজে আপনি কি আমাকে বলতে পারেন।
Source: Cliffs TOEFL, page no:95

Confusion removing explanation for choosing answer it is or it was:
"Could" is a modal verb used to express possibility or past ability as well as to make suggestions and requests.
In the sentence, “Could you tell me” expresses request, it doesn’t express possibility or past ability.
So, “Could you tell me” will follow a sentence which is “it is” (present tense).