A semipro baseball league has teams with 21 players each. League rules state that a player must be paid at least ＄15，000，and that the total of all players’ salaries for each team cannot exceed ＄700，000. What is the maximum possible salary，in dollars，for a single player？

A. 270，000    B. 385，000    C. 400，000    D. 430，000    E.700，000

For real numbers ａ and b， define a＄b＝（a－b）. What is （x－y）＄（y－x）？______