The set of quantum numbers correspond to an electron in a 4d orbital is .
A 4d orbital will always have a value of 4 for the primary quantum number and a value of 2 for the azimuthal quantum number. The possible values of ml for the 4d orbital are -2, -1, 0, 1, and 2 since the range of the magnetic quantum number is from -l to l. ms always has values of +1/2 and -1/2. The 4d orbital can therefore have a total of 10 different quantum number configurations. For instance, n = 4, l = 2, ml = 0, and ms = 1/2.
Hence, the option B is correct.