Step 1: Understanding methods of development. 
  
There are various methods of employee development that help in enhancing their skills and abilities. Job rotation, short-term syllabi, and on-the-job training are all strategies that can contribute to development. 
Step 2: Analyzing the options. 
  
(A) Job rotation method: Correct. Job rotation helps employees gain experience in various functions and roles, enhancing their versatility and skills. 
  
(B) Short-term syllabus: Correct. A short-term syllabus or training program is often used to provide focused learning experiences in a specific area. 
  
(C) Development on the job: Correct. On-the-job development is practical and focuses on skill enhancement through real work experience. 
  
(D) All of these: Correct. All these methods are effective for employee development. 
Step 3: Conclusion. 
  
The correct answer is (D) All of these, as all these methods contribute to employee development.