A proton and an electron are both travelling at the same speed. What can we conclude about their de Broglie wavelengths?

Mass of an electron =9.1 x 10 ^-31 kg

Mass of a proton =1.67 x 10 ^?27 kg

Now de Broglie wavelength is given as

Since speed(v) is same for both the particles ? is inversely proportional to mass.

Since mass of proton is more de Broglie wavelength of the proton will be shorter than that of the electron.

Hence option c is correct and not d.