a. Ge is a group-14 element and In is of group.-13 Group-13 doped crystals of Ge are called p-type semiconductors.
b. `B` is a group-13 ans `Si` is of group-14. They behave like n-type semiconductor in which `Si` (group-14) is doped with group-15 elements (higher group elements). Here `B` is doped with `Si` (higher group elements)
Hence, it behaves an n-type semiconductor.