Step 1: Understanding the advertisement.
The ad line "A newspaper is only as interested as its readers" was coined by The Economic Times. This line reflects the paper's focus on delivering news and content that is highly relevant to its readers.
Step 2: Analyzing the options.
- (a) The Economic Times: Correct, as this is the newspaper associated with the ad line.
- (b) Hindustan Times: Incorrect. This newspaper does not use this ad line.
- (c) The Indian Express: Incorrect. The Indian Express does not have this ad line.
- (d) The Times of India: Incorrect. The Times of India uses different promotional content.
Step 3: Conclusion.
The correct answer is (a), as "A newspaper is only as interested as its readers" is associated with The Economic Times.