I have an electrochemistry question? Not sure if I should convert atm to M?

The standard cell potential (E°) of a voltaic cell constructed using the cell reaction below is 0.76 V: Zn(s)+2H+(aq) --> Zn2+(aq)+H2(g) With PH2 = 1.0 atm and [Zn2+] = 1.0 M, the cell potential is 0.66 V. The concentration of H+ in the cathode compartment is __________ M. A) 4.9 × 101 B) 1.4 × 10-1 C) 4.2 × 10-4 D) 2.0 × 10-2 E) 1.0 × 10-12