It is a good question.
The key statement to focus here is - "Despite a warm reception in the initial days", which means employees attended the program in initial days.
A) most employees were not interested in the training programs.
If employees were not interested, then it would not have had warm reception in intial days..WRONG
B) the employees were not inspired to attend training after their working hours
If employees were not inspired, then it would not have had warm reception in intial days..WRONG
C) the training proved inadequate for practical, smooth transition from one department to the other.
Employees received it warmly but gradually, they found it inadequate and hence the program did not succeed...CORRECT
D) the employees did not like most of the training programs
If employees did not like most of the training program, then it would not have had warm reception in intial days..WRONG
E) the employees were not interested in changing departments
If employees were not interested, then it would not have had warm reception in intial days..WRONG