Which of the following occurs when one consumer sells directly to another consumer, such as in an online auction?

Group of answer choices

consumer$-$to$-$business $($C$2$B$)$ e$-$commerce

business$-$to$-$consumer $($B$2$C$)$ e$-$commerce

consumer$-$to$-$consumer $($C$2$C$)$ e$-$commerce

business$-$to$-$business $($B$2$B$)$ e$-$commerce