Answer
Yes, the answer is b
Work Step by Step
The formula for density is d = PM/RT so gases that are more massive will be more dense than those that are less massive. In the case of Nitrogen (M = 28g/mol) and Xe (M = 131.2 g/mol), the Xe is more massive. Since the two are at STP, so they are under the same conditions, they will have the same number of moles per unit volume. However, since the molar mass of Xe is higher, it will be more dense.
This is choice b
