Doubt From Coordination Chemistry

#1


The correct answer is option (C).
But,how is it possible for Ca^{2+} ion to make 6 bonds?

#2

Ca+2 accepts 6 lone pairs (4 from N + 2 from O) in it's vacant orbitals, by a co-ordinate bond.

#3

Ca2+ will take 6 bond from EDTA as follow
It will form 2 bond from Nitrogen lone pair
And four bond from O-.
See the structure