Correct Answer: a stone’s throw away

Solution : The correct option is the first option.

Explanation:
A stone’s throw away means a very short distance, usually close enough to be reached by throwing a stone. In this context, it implies that APJ Abdul Kalam's house was very close to the famous temple of Rameswaram, within a short distance that could be covered by throwing a stone.

The meanings of the other options are as follows:

• At one’s fingertip means readily available or easily accessible.
• At arm’s length means to keep someone or something at a distance.
• From pillar to post means moving from one place or situation to another without purpose or direction.

Therefore, the complete sentence is: "APJ Abdul Kalam’s house, located on Mosque Street, was within the reach of the famous temple of Rameswaram. It was just a stone’s throw away from it."