If x(t) = tn u(t), then the Laplace transform of x(t) is:

• A. \(\frac{{n!}}{{{s^{n + 1}}}}\)
• B. \(\frac{{n!}}{{{s^n}}}\)
• C. \(\frac{n}{{{s^{n + 1}}}}\)
• D. \(\frac{{n!}}{{{s^{n - 1}}}}\)