A, B, C, or D?

(please help)

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;