Final answer:
When comparing the Maxwell-Boltzmann distributions of two gases at the same temperature, the gas with the larger molar mass will display a narrower distribution with lower most probable speeds.
Step-by-step explanation:
The Maxwell-Boltzmann distribution describes how molecular speeds are distributed in a sample of gas. When comparing the distributions of two different gases at the same temperature, the one with the larger molar mass will have a narrower distribution, and its molecules will be moving slower on average. The distribution with the lower most probable speed indicates the gas with the larger molar mass, because heavier molecules move slower than lighter ones at the same temperature.