A rectangular game board is composed of identical squares arranged in a rectangular array of r rows and r+1 columns. The r rows are numbered from 1 through r, and the r+1 columns are numbered from 1 through r+1. If r>10, which of the following represents the number of squares on the board that are neither in the 4th row nor in the 7th column?
A: r*r-r B: r*r-1 C: r*r D: r*r+1 E: r*r+r
表示读了好几遍都没懂题目什么意思啊...