If 45-[28-{37-(15-*)}]= 56, then * is equal to:  Choose the correct choice from the following options.
A) - 29 B) - 19 C) 17 D) 29 E) 39

Rationale: "45 - [ 28 - { 37 - ( 15 - * ) } ] = 56 = > 45 - [ 28 - { 37 - 15 + * } ] = 56 45 - [ 28 - 37 + 15 - * ] = 56 = > 45 [ 43 - 37 - * ] = 56 45 - [ 6 - * ] = 56 = > 45 - 6 + * = 56 39 + * = 56 = > * = 56 - 39 = 17 answer : c"
Answer: C