Find the Right Part of the Equality $$4 + 5 + 6 + \cdots + ( n + 3 ) =$$

Multiple Choice

Find the right part of the equality. $$4 + 5 + 6 + \cdots + ( n + 3 ) =$$

A) $\frac { n ( 8 n + 7 ) } { 3 }$
B) $\frac { n ( n + 7 ) } { 2 }$
C) $\frac { n ( 5 n + 7 ) } { 3 }$
D) $n ( 5 n - 1 )$
E) $\frac { n ( n + 7 ) } { n }$