GKFix MCQ Question

What is the expression for v2f in a one-dimensional elastic collision?

• A. m1v1i / (m1 + m2)
• B. (m1 - m2)v1i / (m1 + m2)
• C. 2m1v1i / (m1 + m2)
• D. v1i(m1 + m2)/m1