If a - b = 3 and a^2 + b^2 = 29, find the value of ab.	Choices: A) 5 B) 10 C) 12 D) 14 E) 15

Rationale: "2 ab = ( a ^ 2 + b ^ 2 ) - ( a - b ) ^ 2 = 29 - 9 = 20 ab = 10 . b )"
Answer: B