If f(t) = cos(at) + atsin(at), its Laplace transform is given by?

• A. \(\frac{s+a}{s-a}\)
• B. \(\frac{a^3}{(s^2+a^2)^2}\)
• C. \(\frac{s(s^2+3a^2)}{(s^2+a^2)^2}\)
• D. Does not exist