A rectangle with dimensions 75 inches by 100 inches is divided into 20 smaller rectangles. If each new rectangle has equal dimensions, how many inches of lines are needed to divide the original rectangle ？（）
(1)One of the dimensions of each of the rectangles is 15 inches.
(2)One of the dimensions of each of the rectangles is 25 inches.
A．条件(1)充分，但条件(2)不充分．
B．条件(2)充分，但条件(1)不充分．
C．条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D．条件(1)充分，条件(2)也充分．
E．条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．
