It is about time you … to bed.

Analyze the question The sentence is "It is about time you __ to bed." We need the correct verb form after the structure "It is (about/high) time + subject."

Explain the concept After "It is time / It's about time / It's high time" followed by a subject, English uses the simple past tense to show that the action should already be happening or should have started. The past tense here does not refer to past time. It expresses a present or future need, often with a hint of criticism or urgency.

Examples:

• It is high time we left.
• It's about time he learnt to be responsible.

Other patterns exist, such as "It is time for you to go" or "It is time you should go". The "should" form is possible in some grammar books, but the standard and most tested form is the simple past.

Solution, option by option

• A. go: the present form is not used in this structure. ✗
• B. have gone: the present perfect does not fit, because the action has not yet happened. ✗
• C. went: the simple past is the standard form after "It is about time + subject." ✓
• D. should go: this is occasionally acceptable in British usage, but it is less standard than the past tense and is not the best answer here. ✗

Answer The best answer is C. went.

Tip Whenever you see "It is (high/about) time + subject", choose the simple past tense. Remember: "Time is up, so use the past."