At one's fingertips

Answer: Option C

Explanation:

Example: All formula's of quantitative aptitude are at his fingertips.

Answer: Option C

Explanation:

Example : My leg has hurt while playing now I have a Charley horse.

Answer: Option A

Explanation:

This is a treat that gives you plenty of bang for the buck

Answer: Option B

Explanation:

Example : As he slipped on the bank of river, he had a close shave.

Answer: Option B

Explanation:

Example : Police has an ability to made anyone spill the beans.