A perfect crystal of silicon (fig) is doped with some elements as given in the options. Which of these options shows n -type semiconductors?

When group l5 elements are doped into a perfect crystal of Si, it leads to the formation of n -type semiconductor.Here, in (a) As (group 15, period 3) is doped to perfect Si crystal and in (c) P (group 15, period 2) is doped to perfect Si-crystal.