If a and b are positive integers, a > b and (a + b)2 - (a - b)2 > 29 Then the smallest value of a is -

Answer: Option B

Since (a + b)² - (a - b)² = 4ab, So, the given expression should be a multiple of 4
So, the least value of 4ab is 32 and so the least value of ab is 8
Hence, the smallest value of a is 4 and that of b is 2
Hence, a = 4