She would have helped if she ______ asked.

• A. Has
• B. Had
• C. Have
• D. Having

Answer: (B)

Unreal past conditions are expressed with a past perfect in the if-clause and would have plus a past participle in the main clause. Here the main clause is “She would have helped,” so the if-clause needs the past perfect form of “ask”: “had asked.” That gives the natural, correct construction: “She would have helped if she had asked.”

Using present perfect forms like “has asked” or “have asked” would place the action in relation to now and don’t carry the same unreal past meaning. “Having asked” isn’t the right structure for this conditional sentence either. So the past perfect fits the pattern and the intended past-unreal meaning.