The clock … 12 o'clock two hours ago.

Step 1: Analyze the question We need the correct verb form to fill the gap in: "The clock _ 12 o'clock two hours ago."

Step 2: Identify the key clue The phrase "two hours ago" tells us the action happened at a definite time in the past. This means we need the simple past tense.

Step 3: Explain the concept Time expressions like ago, yesterday, last week and in 2010 go with the simple past tense.

The verb strike is irregular:

• Present: strike / strikes
• Past: struck
• Past participle: struck (or stricken in some uses)

Step 4: Test each option

• A. Striking: "The clock striking 12 o'clock two hours ago" is incomplete and has no finite verb. ❌
• B. Strikes: present tense, which clashes with "ago". ❌
• C. Strike: base form or plural present, which is wrong with a singular subject and a past time. ❌
• D. Struck: simple past, which fits "two hours ago". ✅

Correct sentence: "The clock struck 12 o'clock two hours ago."

Tip: In JAMB English, whenever you see ago, think simple past. Also learn common irregular verbs such as strike-struck, ring-rang, begin-began and drive-drove, because they are tested often.