Silicon forms a very large number of compounds containing `SiO_(4)^(4-)` anion as the basic unit. The structure of this basic unit is a tetrahedron in which oxygen atoms are arranged tetrahedral around a silicon atom.
The total number of oxygen shared per tetrahedron in Beryl `[Be_(3)Al_(2)Si_(6)O_(18)]`
A. 4
B. 3
C. 2
D. 1