GKFix MCQ Question

If φ = π, what is the expression for the resultant wave?

• A. y(x,t) = 2a sin(kx – ωt)
• B. y(x,t) = a sin(kx – ωt)
• C. y(x,t) = 0
• D. y(x,t) = a cos(kx – ωt)