The correct option is A had been making
The past perfect continuous form of any verb is obtained by adding 'had been' to the base verb + ing. The verb in question is 'to make'; for which the base/ root form is simply 'make'. Applying the above, we clearly get 'had been making', which is Option A) - the correct answer. B) is simply past perfect tense; C) is past continuous and lastly, D) is simple past tense.