If $A$,$E$,$M$,and $n$ represent atomic mass,equivalent mass,molecular mass,and valency of an element respectively,which of the following relations is correct?

• A
  $A = E \times n$
• B
  $A = \frac{M}{E}$
• C
  $A = \frac{M}{n}$
• D
  $M = A \times n$