Obviously, it is the reward obtained by using one's brains and spending intellectual labor, so it is the income obtained by A distributed according to the factors of production. Only when Li Yang has put in labor and meets the needs of the other party (market) can his labor be useful and can he be paid.

B refers to the income obtained from obtaining an individual business license and specializing in self-employment. Li Yang was a student and accidentally participated in the competition.

C and A are similar, but A is more in line with the meaning of the question. Everyone who submitted the article has worked hard, and some may have paid more, but only Li Yang's work won the award, so the income is not based on the amount of labor.

D. Obviously, in order to be able to produce works, Li Yang’s parents have to invest capital in education and cultivation. However, other people may have spent more time, capital and money to acquire creative abilities, but their works will be sold by the market. Income derived from need.