Let us frame the equation:
a+b is divisible by 4,
substituting the value of a in terms of b: a=2b-10
3b-10 is divisible by 4.
Working with answer choices (plugging in the choices for b in the above equation)
6, we end up at 8, divisible by 4.
8, 14 not divisible by 4, hence the answer is 8
Hence the answer is option B