Explanation:

Correct Option: D
Statement 1: fine cloth                                 Code Statement 1: oka peru
Statement 2: clear water                              Code Statement 2: meta lisa
Statement 3: fine clear weather                   Code Statement 3: dona lisa peru
In the 1st and 3rd statements, the common code-word is 'peru' and the common word is 'fine'. So, 'peru' means 'fine'.
In the 2nd and 3rd statements, the common code-word is 'lisa' and the common word is 'clear'. So, 'lisa' means 'clear'.
Thus, in the 3rd statement, 'lisa' means 'clear' and 'peru' means 'fine'. So, 'dona' means 'weather'.
Hence, the answer is option D.
Short-cut Method:
As we have to find the code-word for the word 'weather' which is coming only in the 3rd statement, we can find it by removing the code-words for other two words that are coming with 'weather' in the Statement 3 and are being repeated once in the given statements.
Note: It's of no use which particular code-word the other two words except 'weather' stand for.
Now, in the code statements, we can see that 'lisa' and 'peru' are being repeated twice, we, therefore, remove them. The code-word that is left is 'dona' which evidently stands for 'weather'.
Hence, the answer is option D.