Choose the grammatically correct sentence:

The correct answer is Option (1) → Papa reached the fuel station on the little petrol left in his scooter.

The little and the few:

• The little means all of the small amount there is. It goes with uncountable nouns (things we cannot count).
• “Petrol” cannot be counted, and “left in his scooter” points to all of that small amount. So “the little petrol” is correct.

Why the Other Options are Incorrect?

Option 2: Riya gave the few water left in her bottle to a tired runner. — Incorrect. “Few” goes with countable nouns, but “water” is uncountable.
Corrected: Riya gave the little water left in her bottle to a tired runner.

Option 3: Kunal answered the little questions he knew in the science quiz. — Incorrect. “Questions” can be counted, so it needs “the few”, not “the little”.
Corrected: Kunal answered the few questions he knew in the science quiz.

Option 4: Dinesh lent the fewer pencils he owned to his classmates before the drawing test. — Incorrect. “Fewer” is used to compare two numbers (fewer than). For all of a small number we use “the few”.
Corrected: Dinesh lent the few pencils he owned to his classmates before the drawing test.