Which e$-$commerce model involves businesses selling directly to individual consumers over the internet?

Question $10$ options:

Business$-$to$-$Business $($B$2$B$)$

Business$-$to$-$Employee $($B$2$E$)$

Business$-$to$-$Consumer $($B$2$C$)$

Consumer$-$to$-$Consumer $($C$2$C$)$