Correct Answer: 2, 1, 5, 3, 4

Solution : Given:
1. Sermonize  2. Serious 3. Servant 4. Session 5. Serrated

Step 1: Compare the first and second letters of each word. Since all the words start with the same letter S and are followed by e , then move on to the next letter.
Step 2: The third letter of each word is either r or s . Based on the alphabetical order of these letters, we can arrange them – Se r monize, Se r ious, Se r vant, Se r rated, Se s sion
Step 3: Compare the fourth letter of (Ser m onize, Ser i ous, Ser v ant, Ser r ated). Based on the alphabetical order of these letters, we can arrange them – Ser i ous, Ser m onize, Ser r ated, Ser v ant.

So, the sequence is Serious, Sermonize, Serrated, Servant, Session or 2, 1, 5, 3, 4. Hence, the fourth option is correct.