In the following question, out of the four alternatives, select the alternative which will improve the bracketed part of the sentence. In case no improvement is needed, select "no improvement".
The study of individual markets of demand and supply in which the 'players', or the decision makers, were also individuals (buyers or sellers, even companies) who were seen as trying to maximize their profits (as producers or sellers) and their personal satisfaction or welfare levels (as consumers) is called?