Which of the following statements is/are correct?

• A

  The co-ordination number of each type of ion in CsCl crystal is 8 

• B

  A metal that crystallizes in b.c.c. structure has a co-ordination number of 12

• C

  A unit cell of an ionic crystal shares some of its ions with other unit cells

• D

  The length of the unit cell in NaCl is 552 pmm $\left({\mathrm{r}}_{{\mathrm{Na}}^{+}}=95\mathrm{pm},{\mathrm{r}}_{{\mathrm{Cl}}^{-}}=181\mathrm{pm}\right)$