Express the Sum in Sigma Notation $$6 + 7 + 8 + 9 + 10 + 11$$

Express the sum in sigma notation.
- $$6 + 7 + 8 + 9 + 10 + 11$$

A) $\sum _ { k = 6 } ^ { 5 } k + 6$
B) $\sum _ { \mathrm { k } = - 1 } ^ { 0 } ( - 1 ) ^ { 2 \mathrm { k } } \mathrm { k }$
C) $\sum _ { k = 0 } ^ { 5 } k + 6$
D) $\sum _ { \mathrm { k } = 0 } ^ { 5 } \mathrm { k }$