If \(a\) and \(b\) are distinct positive integers, what is the units digit of \(2^a\cdot 8^b\cdot 4^{a+b}?\)

[M7MBA]

If \(a\) and \(b\) are distinct positive integers, what is the units digit of \(2^a\cdot 8^b\cdot 4^{a+b}?\)

(1) \(b = 24\) and \(a < 24.\)
(2) The greatest common factor of \(a\) and \(b\) is \(12.\)

Answer: B

Source: Manhattan GMAT