Litmus test is a common test to check:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Acidic & Basic Nature of Solution
Litmus is a natural dye obtained from lichens and used as an acid-base indicator. An acid turns blue litmus red, and a base turns red litmus blue; a neutral solution changes neither.
Why the other options are incorrect
Option (2) Rancidity of substance — Incorrect. Rancidity is the oxidation of fats and oils, judged by smell and taste, not by litmus.
Option (3) Nutritional content of Fruit — Incorrect. Nutrients are measured by chemical food analysis; litmus shows only acid or base.
Option (4) Test Blood Sugar — Incorrect. Blood sugar is checked with a glucometer or laboratory glucose test.