Step 1: Understanding the Four Yugas. 
  
In Hindu cosmology, the Four Yugas represent the four ages that span the entire cycle of creation:  
- A. Treta: The second age in the cycle, marked by virtue and righteousness.  
- C. Sat: The first and golden age, characterized by truth and purity.  
- D. Kali: The current age, marked by conflict, strife, and moral decline.  
- B. Dwarak: This is not traditionally one of the Four Yugas.  
Step 2: Conclusion.  
The correct Yugas are A, C, and D only.  
  
 
Final Answer:  
\[  
\boxed{\text{The correct answer is 4. A, C and D only.}}  
\]