Your Answer is

Correct Answer is G

Explanation

Square both sides of the equation at the same time, (ax+b)²=(bx+a)², remove the brackets to get a²x²+2abx+b²=b²x²+2abx+a², a²x²+b²=b²x²+a², a²x²-b²x²= a²-b², x²=(a²-b²)/(a²-b²)=1, so x=±1