Which expression equals (a+b)2(a + b)^2(a+b)2?
a2+2ab+b2a^2 + 2ab + b^2a2+2ab+b2
a2+b2a^2 + b^2a2+b2
a2−2ab+b2a^2 - 2ab + b^2a2−2ab+b2
a2−b2a^2 - b^2a2−b2