Consider a cost function of the formC$($x$)=\{20,000+980$x$$x$^2$for$0$x$<1,0000$for$$x$1,000.$Which of the following gives the correct representation for the marginal cost?

Select the correct answer below:

MC$=$C$($x$)=\{9802$x$$for$0$x$<1,0000$for$$x$1,000.$

MC$=$C$($x$)=9802$x$$for$0$x$<1,0000$for$$x$>1,000$Undefined$$for$$x$=1,000.$

MC$=$C$($x$)=20,000$x$+980$x$$for$0$x$<1,0000$for$$x$1,000.$

MC$=$C$($x$)=9802$x$,$