The word "people" is a countable noun, so we use "few" to describe it.
The correct sentence should be:
"There are few people on the beach."
Thus, the correct answer is "few" (Option C).
Arun’s present age in years is 40% of Barun’s. In another few years, Arun’s age will be half of Barun’s. By what percentage will Barun’s age increase during this period?