The Dharmachakra in the National Flag of India is a representation of the Dharma Chakra; a wheel that appears on the Sarnath Lion Capital of Ashoka. It has 24 spokes, as indicated in option 4.

Option 1 suggests there are 16 spokes which is incorrect. Similarly, Option 2 states there are 18 spokes, and option 3 says there are 22 spokes - both of these are also incorrect.

Each spoke in the Dharmachakra represents a valuable virtue which are reflective of ideals intrinsic in the concept of `dharma` in Indian philosophy. The Dharmachakra is indicative of justice in all aspects of life, a central philosophy in the Indian perspective and hence forms a prominent part of the Indian national flag.

So, the correct number of spokes in the Dharmachakra in the National Flag of India is indeed 24, making option 4 the correct answer.