To express a hexa-decimal number to its binary equivalent, each hexa-decimal digit is expressed as

1. 2 bits form
2. 3 bits form
3. 4 bits form
4. None

4 bits form

Reason — Since the digits from 0 to 15 need a maximum of 4 bits to be represented in binary form hence in Hexa-decimal to Binary conversion each hexa-decimal digit is expressed as 4 bits form.