If page fault service time is 50 milli second and memory access time is 100 ns, then what will be EMAT, if the probability of page fault is $p$ ?
a) $500000 + 100p$ ns
b) $100 + 500000p $ ns
c) $10^{-7} - 5 p\times 10^{-2}$ seconds
d) $10^{-7} + 49.9p \times 10^{-3}$ seconds