Find the convolution of the signals x1 (t) = e-2t u(t) and x2 (t) = e-3t u(t).

• A. e^-2t u(t) e^-3t u(t)
• B. e^-2t u(t) + e^-3t u(t)
• C. e^2t u(t) e^3t u(t)
• D. e^2t u(t) e^-3t u(t)