Simplfy
b - [b -(a+b) - {b - (b - a+b)} + a] Choose the most appropriate option:
A) a
B) 2a
C) 4a
D) 0
E) 1
Explanation:   b-[b-(a+b)-{b-(b-a+b)}+a]   =b-[b-a-b-{b-(2b-a)}+a]   =b-[-a-{b-2b+a}+a]   =b-[-a-{-b+a}+a]   =b-[-a+b-a+a]   =b-[-2a+b+a]   =b-b+a   =a   Option a
<result>A</result>
Simplfy
b - [b -(a+b) - {b - (b - a+b)} + a]