Solve the Problem $7 \cdot ( 0.90 ) + 7 \cdot ( 0.90 ) ^ { 2 } + 7 \cdot ( 0.90 ) ^ { 3 } + \ldots$

Multiple Choice

Solve the problem.
-England decides to decrease its taxes by £7 billion. It is estimated that of each pound received, a typical citizen will spend 90%. The level of economic activity generated by the tax cut is therefore estimated to be: $7 \cdot ( 0.90 ) + 7 \cdot ( 0.90 ) ^ { 2 } + 7 \cdot ( 0.90 ) ^ { 3 } + \ldots$ billion pounds. This amount is equal to what?

A) £63 billion
B) £70 billion
C) £3.6 billion
D) £45 billion
E) none of these