On the basis of van der Waals constants a and b for two gases H₂ and O₂ choose the correct statement from the following.
a. Value of b for O₂ is more while value of a is more for H₂
b. Value of b for H₂ is more while value of a is more for O₂
c. Value of both a and b is more for H₂
d. Value of both a and b is more for O₂
