What is the final product (major) 'A' in the given reaction ?

The product formed in the first step of the reaction of


with excess $$\mathrm{Mg/Et_2O}$$ ($$\mathrm{Et=C_2H_5}$$) is

Number of amphoteric compounds among the following is ________.
(A) BeO
(B) BaO
(C) Be(OH)₂
(D) Sr(OH)₂

The coordination number of an atom in a body-centered cubic structure is _______.
[Assume that the lattice is made up of atoms.]