The correct answer is B. The thief ran away from the scene when he saw a policeman on the beat.
Option A is incorrect because the thief did not have any pain in his heels. Option C is incorrect because the thief did not confront the policeman. Option D is incorrect because the thief did not hesitate or have trouble deciding what to do.
The phrase “took to his heels” means to run away quickly. In this case, the thief was running away from the scene of a crime. He was trying to escape from the police.