Write the Given Series in Summation Notation $2 - 4 + 8 - 16 + 32 - 64 + 128$

Multiple Choice

Write the given series in summation notation. $2 - 4 + 8 - 16 + 32 - 64 + 128$

A) $\sum _ { i = 1 } ^ { 7 } 4 ^ { i } ( - 1 ) ^ { i }$
B) $\sum _ { i = 1 } ^ { 7 } 4 ^ { i } ( - 1 ) ^ { i + 1 }$
C) $\sum _ { i = 1 } ^ { 7 } 2 ^ { i } ( - 1 ) ^ { i + 1 }$
D) $\sum _ { i = 1 } ^ { 7 } 2 ^ { i } ( - 1 ) ^ { i }$
E) $\sum _ { i = 1 } ^ { 7 } 3 ^ { i } ( - 1 ) ^ { i }$