If a and b are two odd prime numbers such that a > b, then a² − b² is:

Correct option is D

Given:

a and b are odd primes, so both are odd numbers.

Concept used:
Difference of squares:
a² − b² = (a − b)(a + b)

Solution:
Since both a and b are odd,
→ (a − b) is even,
→ (a + b) is even.

Hence, (a − b)(a + b) = even × even = even number.

Correct answer is (d) an even number.