Correct Answer: Less

Solution : Given:
1. Leaf 2. Less 3. Lean 4. Leave

Step 1: Since all the words start with the same letter L . So, move on to the next letter.
Step 2: The second letter of each word is the same, i.e., e . So, move on to the next letter.
Step 3: The third letter of each word is either a or s . The arrangement can be – (Leaf, Lean, Leave), or Less.
Step 4: Compare the fourth letter of (Lea f , Lea n , Lea v e). Leaf will come before Lean, and Leave as f comes before n , and v according to the alphabetical system. Similarly, Lean will come before Leave as n comes before v according to the alphabetical system.
Therefore, the sequence is Leaf, Lean, Leave, Less, or 1, 3, 4, 2.

So, the word Less appears last when arranged in the order of the dictionary. Hence, the third option is correct.