A natural gas (methane, CH₄) storage facility uses 3-cm-diameter by 6-m-long vent tubes on its storage tanks to keep the pressure in these tanks at atmospheric value. If the diffusion coefficient for methane in air is 0.2 ×10^-4 m²/s and the temperature of the tank and environment is 300 K, the rate at which natural gas is lost from a tank through one vent tube is
(a) 13 × 10^-5 kg/day

(b) 3.2 × 10^-5 kg/day

(c) 8.7 × 10^-5 kg/day

(d) 5.3 × 10^-5 kg/day

(e) 0.12 × 10^-5 kg/day