Frankly speaking, both deficiencies and defects have same meaning, problem / shortcoming / something lacking etc. So both (a) and (b) should be correct logically, but as per text in study material (b) is correct. From english point of view quantities is in plural and hence deficiencies is more suitable with deficiencies. Our team picked this sentence from study material. Below is link and its reference. You can mark it as C category MCQ, such MCQs generally wont come in exams.
Page 9.9 Last Para 9.1.6 Line Number 6
Thankyou Sir. So thorough reading of Study material also is necessary.Right? I am now studying and reading practice manual only.
Studying SM line by line and remembering it is not possible, have good conceptual clarity cover PM + 4 Attempt RTP / MTP / Suggested Answers + Application Based MCQs
Any Reference Book & Class if you are facing lot of problems in understanding and retaining audit
See this video on application based mcqs https://youtu.be/osvJ5WABnW4