If \(r, s,\) and \(t\) are all positive integers, what is the remainder of \(\dfrac{2^p}{10},\) if \(p = rst?\)

[Vincen]

If \(r, s,\) and \(t\) are all positive integers, what is the remainder of \(\dfrac{2^p}{10},\) if \(p = rst?\)

(1) \(s\) is even
(2) \(p = 4t\)

Answer: B

Source: Manhattan GMAT