The coefficient of \( x^{301} \) in \( (1+x)^{500} + x(1+x)^{499} + x^{2}(1+x)^{498} + \ldots + x^{500} \) is:
\( {}^{500}C_{301} \)
\( {}^{501}C_{302} \)
\( {}^{500}C_{300} \)
\( {}^{501}C_{200} \)