Answer
See explanation below.
Work Step by Step
a.) [Ar] 4s2 3d10 4p2 is Ge (Germanium). The other elements in this group are C, Si, Sn, Pb, Fl
b.) [Ar] 4s2 3d7 is Co (Cobalt). The other elements in this group are Rh, Ir, Mt
c.) [Kr] 5s2 4d5 Tc (Technetium). The other elements in this group are Mn, Re, Bh