A
1 and 2
B
Only 3
C
2 and 3
D
Only 1
Correct answer: (b) Only 3
Explanation
- A
1 and 2
1 and 2. Lactic–curd and tartaric–grapes are correct NCERT pairs.
- B
Only 3
Only 3. Acetic acid is vinegar, not potato. Potato is often listed with oxalic / starch, not acetic.
- C
2 and 3
2 and 3. Tartaric–grapes holds.
- D
Only 1
Only 1. Lactic–curd holds.
Summary. Official key is (b) only 3. Acetic acid is not the potato acid. Also note: Lactic — Curd / sour milk; Tartaric — Grapes, tamarind; Acetic — Vinegar; CH3COOH; Oxalic — Sometimes cited for tomato/potato traps.