B is correct, because you have to use the same tense in this sentence. The tense used is Past Perfect, which consists of a person + had + verb Past Participle. Other example: She had her car fix this month, hadn't she?

B is probably technically correct, but you would most commonly hear A. Not all English speakers know the correct grammar!

Thanks Peachey for pointing it out!! :)

The correct answer is actually A. This is not a perfect tense, but a causative verb. Objects don't fit in between the perfect tense pattern.