One of the following antibiotics is resistant to penicillinase - Penicillinase Resistant Penicillins

One of the following antibiotics is resistant to penicillinase:
a- penicillin V
b- penicillin G
c- floxapen
d- ampicillin
e-amoxicillin

Penicillinase Resistant Penicillins:
Dicloxacillin, Naficillin, Oxacillin