Step 1:
Degree of competition refers to the intensity of rivalry among firms.
Step 2:
• Perfect Competition $\rightarrow$ Highest competition
• Monopolistic Competition $\rightarrow$ High competition with differentiation
Step 3:
• Oligopoly $\rightarrow$ Few firms dominate
• Monopoly $\rightarrow$ No competition
Step 4:
Descending order:
\[
C,\; B,\; D,\; A
\]
Hence, the correct answer is:
\[
\boxed{\text{(1) C, B, D, A}}
\]