Explanation
- A
1, 3 and 4 only
(a) 1, 3 and 4 only. Food printing, auto parts and reconstructive surgery are real 3D-printing uses, but bionic ears and data-processing/electronics printing are also documented. Dropping 2 and 5 is therefore incomplete. This option is not the key.
- B
2, 3 and 5 only
(b) 2, 3 and 5 only. It keeps bionic ears, autos and data hardware but omits confectionery and surgery, which additive manufacturing already serves. This option is not the key.
- C
1 and 4 only
(c) 1 and 4 only. Far too narrow: cars, medical devices and printed electronics are missing. This option is not the key.
- D
1, 2, 3, 4 and 5
(d) 1, 2, 3, 4 and 5. Additive manufacturing prints sugar/chocolate forms, tissue-engineered/bionic ears, automotive prototypes and parts, surgical implants/guides, and even electronic/data-processing hardware (printed circuits, housings). All five listed fields apply. This option is the official key.
Summary. Official key is (d) 1, 2, 3, 4 and 5. Three-dimensional printing is a general fabrication method: food pastes, biomedical scaffolds and bionic ears, vehicle parts, reconstructive implants, and printed electronics for data devices. None of the five listed areas is outside that envelope as UPSC framed it. Partial codes therefore under-count. The Set A key is all five.
Same topic · past papers
UPSC has asked this before
These previous-year questions sit on the same topic. Open one to practise the earlier ask.