Rms speed at given temperature is given as

v_rms =

where R=gas constant whose value is 8.31 J/mol K.

T=temperature of gas.

M= molar mass of molecule of gas

Therefore, at a given temperature rms speed of gas is inversely proportional to square root of molar mass of molecule of that gas.

Out of the four-option molar mass of hydrogen molecule is least

i.e. 2 amu. So rms speed of hydrogen will be maximum.