The correct answer is b. bimolecular
Hydrogen is a non-polar gas with very weak intermolecular forces of attraction. Hydrogen will deviate from the ideal gas behavior at high pressure.
Answer: Boyle's law
Explanation: It states that pressure of a gas is inversely proportional to the volume of a gas at constant temperature.
∝
at constant temperature
or If the pressure of gas is decreased, the volume increases if the temperature is unchanged and If the pressure of gas is increased, the volume decreases if the temperature is unchanged.

What they have in common is that they both have the same number of atoms.