Select the most appropriate option to fill in the blank. The smoke coming out of the factory chimneys was polluting the air, which was becoming a major _______ for the local residents.

Correct option is A

The correct option to fill in the blank is (a) concern.
· Explanation: "Concern" fits the context as it refers to a matter that causes worry or distress, which aligns with the air pollution affecting local residents. (Hindi: चिंता का कारण)
· Example: Rising pollution levels are a growing concern for authorities.
Why Other Options Are Incorrect:
· Idea: Refers to a concept or thought (Hindi: विचार).
· Law: Refers to a set of rules (Hindi: कानून).
· Area: Refers to a region or space (Hindi: क्षेत्र).