${?}_{{?}_{{?}_{?}}{?}_{{?}_{?}}{?}_{{?}_{?}}{?}_{i}s\text{t}\text{h}\text{e}\text{p}\text{r}\text{o}\text{c}\text{e}\text{s}\text{s}\text{w}\text{h}\text{e}\text{r}\text{e}\text{b}\text{y}\text{i}\text{n}\text{d}\text{i}\text{v}\text{i}\text{d}\text{u}\text{a}\text{l}\text{s}\text{d}\text{e}\text{c}\text{i}\text{d}\text{e}\text{w}\text{h}\text{a}\text{t}\text{,}\text{w}\text{h}\text{e}\text{n}\text{,}\text{w}\text{h}\text{e}\text{r}\text{e}\text{,}\text{h}\text{o}\text{w}}$

and from whom $to$ purchase goods and services.

Question $17$ options:

Consumer behavior

Seller behavior