f(t) = t, then its Laplace transform is?

• A. ( frac{(s)sin(b)+acos(b)}{s^2+a^2} )
• B. ( frac{2as^2}{(s^2+a^2)^2} )
• C. ( frac{ Gamma(p+1)}{s^{p+1}} )
• D. 1/s²