The correct answer is D. Kishan and Chander were guilty.
The statement “All guilty politicians were arrested” means that if a politician is guilty, then they will be arrested. The statement “Kishan and Chander were among those arrested” means that Kishan and Chander were arrested. Therefore, it follows that Kishan and Chander were guilty.
The other options are incorrect. Option A is incorrect because the statement does not say that all politicians are guilty. Option B is incorrect because the statement does not say that all arrested people are politicians. Option C is incorrect because the statement does not say that Kishan and Chander were not politicians.