In a crystal structure of an element, atoms are present in ccp arrangement and tetrahedral voids, wh — AITS & Test Series Chemistry Question

Question

In a crystal structure of an element, atoms are present in ccp arrangement and tetrahedral voids, which of the following relation between the atomic radius and edge length is correct for the unit cell which is formed in this arrangement? (a is the edge length and R is the radius of atom): (A) 2 4 a R (B) 3 8 a R (C) 3 4 a R (D) 2 a R