Answer: Option (c) is the correct answer.
Step-by-step explanation:
The diagram represents water cycle. Step 1 shows liquid water from the sea evaporates into the atmosphere in step 2.
Then step 3 shows that water in the form of vapor again changes into liquid state and reaches back into the sea in step 4.
Hence, we can conclude that number 3 in this diagram represents the process of water vapor becoming liquid.