For the Image Shown Below, Choose Which Line Represents the Gas

For the image shown below, choose which line represents the gas with the lowest molar mass.The x-axis represents the molecular speed in m/s and the y-axis represents the number of atoms.

A) The tallest, narrowest line
B) The shortest, widest line
C) The second tallest, second narrowest line
D) The third tallest, third narrowest line