Which of the following statements can be properly inferred from the statements above? A. In 1973 the demand for boats exceeded the supply, while in 1987 the supply of boats exceeded the demand. B. People were willing to invest a greater proportion of their income in boats in 1987 than they were in 1973. C. Between 1973 and 1987, there was a gradual increase in the proportion of large and luxuriously equipped boats sold. D. The average (mean) price of boats sold in 1973 was less than that of boats sold in 1987. E. Between 1973 and 1987, the number of new boats being made increased.