The correct option is D 7
In the first and the second statements , the common code digit is '4' and the common word is 'green'. So, '4' means 'green'. In the first and third statements, the common code digit is '6' and the common word is 'are'. So, '6' means 'are'.
Thus, in the first statement, '7' stands for 'leaves'.
Hence, option (C) is the correct answer.