Hello. You did not present the answer options, which makes it impossible for your question to be answered accurately.
However, we can say that the biggest elements that exist in a market economy, but do not exist in a capitalist system is the production of goods and services determined by the concepts of demand and supply. This is because in the market economy, the production of goods and services is determined by these two elements, whereas in the communist system, this production is determined by the government.