Evaluate the Sum $$\sum _ { \mathrm { k } = 1 } ^ { 4 } ( - 1 ) ^ { \mathrm { k } \cdot 9 \mathrm { k } }$$

Multiple Choice

Evaluate the sum. Round to two decimal places, if necessary.
- $$\sum _ { \mathrm { k } = 1 } ^ { 4 } ( - 1 ) ^ { \mathrm { k } \cdot 9 \mathrm { k } }$$

A) 6561
B) 90
C) 18
D) $- 90$