Topic: Antonyms, Subject: English Grammar (ইংরেজি গ্রামার)

Best Answer Explained in Below-:

The term "onerous" refers to something that is burdensome, oppressive, or requiring significant effort, often accompanied by difficulty and discomfort. When seeking antonyms of "onerous," we look for words that convey the opposite meaning—suggesting ease, lightness, or a lack of burden.

Option A, "Light," is the most fitting antonym. In this context, "light" implies something that is easy to handle, free of heavy demands, or not overwhelming. For example, a "light" task is one that requires minimal effort and is manageable, contrasting sharply with an "onerous" one, which could be considered exhausting or demanding.

In comparison, options B ("Difficult"), C ("Friend"), and D ("Fluent") do not serve as appropriate antonyms. While "difficult" directly opposes the idea of ease, it aligns more with onerous rather than contrasting it. "Friend" and "fluent" are unrelated concepts that don’t pertain to the burdensome quality of the word "onerous." Thus, "light" is the most accurate choice as it succinctly conveys an absence of burden, making it the clear antonym.