2. A square floor is fully covered with equally sized square tiles, with black tiles on the two diagonals and white tiles elsewhere, as shown in the figure. If a total of 101 black tiles are used to cover the floor, then the total number of tiles used to cover the floor is
A. 625
B. 676
C. 2500
D. 2601
2. D Only consider the number of black tiles in the " " direction (or the "/" direction), which is 51 tiles. And this is exactly the number of rows and columns of the floor tiles. Thus, the total number of tiles used to cover the floor is \(51^{2}=2601\). Therefore, the answer is D.