\(A\) and \(B\) can do a piece of work in \(45\) days and \(40\) days respectively. They began to do the work together but \(A\) leaves after some days and then \(B\) completed the remaining work in \(23\) days. The number of days after which \(A\) left the work was
A. \(12\)
B. \(11\)
C. \(10\)
D. \(9\)
E. \(8\)
The OA is D