Answer:
A. MOLES
Explanation:
Quantity of a gas is measured in moles. One mole of a gas substance is the amount of particles present in the substance as the number of atoms in exactly 12grams of carbon-12.
1 mole of carbon-12 or 12grams of carbon-12 contain 6.02 * 10^23 atoms and this is known as the Avohadro number.
Mathematically, number of mole is written as :
Number of moles = number of particles / 6.02 * 10^23.
