The word "bread" is an uncountable noun, meaning it cannot be counted directly. However, we can count "loaves of bread."
The correct phrase should be:
"A loaf of bread."
Thus, the correct answer is "a loaf of" (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?