What does $"\frac{2}{10}$ mean, with respect to "credit terms of $\frac{2}{10},\frac{n}{30}"?$

A$.$ Interest of $2$ percent will be charged if the invoice is paid after $10$ days from the date on the invoice.

B$.$ Interest of $10$ percent will be charged if invoice is paid after two days.

C$.$ A discount of $2$ percent will be allowed if the invoice is paid within $10$ days of the invoice date.

D$.$ A discount of $10$ percent will be allowed if the invoice is paid within two days of the invoice date.