Answer:
36.92 mg of oxygen required for bio-degradation.
Explanation:

Mass of benzene = 30 mg = 0.03 g (1000 mg = 1 g )
Moles benzene =
According to reaction 5 moles of benzene reacts with 15 moles of oxygen gas.
Then 0.0003846 mol of benzene will react with:
of oxygen gas
Mass of 0.0011538 moles of oxygen gas:
0.0011538 mol × 32 g/mol = 0.03692 g = 36.92 mg
36.92 mg of oxygen required for bio-degradation.
Explanation:
1. Boyle's Law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
(At constant temperature and number of moles)

2. Charles' Law states that volume is directly proportional to the temperature of the gas at constant pressure and number of moles.
(At constant pressure and number of moles

3. Gay Lussac's Law states that tempertaure is directly proportional to the pressure of the gas at constant volume and number of moles of gas
(At constant volume and number of moles)

I think it’s B 5.54 x 10^2g