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

Solution : Given:
1. Continuation 2. Contention 3. Contain 4. Continuous 5. Count

Step 1: Compare the first letter of each word. Since all the words start with the same letter C, then move on to the next letter.
Step 2: The second letter of each word is the same, i.e., o. So, move on to the next letter.
Step 3: The third letter of each word is either n or u. Based on the alphabetical order of these letters, we can arrange them – Continuation, Contention, Contain, Continuous, Count.
Step 4: The fourth letter of (Continuation, Contention, Contain, Continuous) is the same, i.e., t. So, move on to the next letter.
Step 5: Compare the fifth letter of (Continuation, Contention, Contain, Continuous). Contain will come before Continuation, Contention, and Continuous in the sequence as a comes before i and e. Similarly, Contention will come before Continuation, and Continuous as e comes before i.
Step 6: The sixth and the seventh letters of Continuation and Continuous are the same, i.e., n and u. So, move on to the next letter.
Step 7: Compare the eighth letter of (Continuation, Continuous). Continuation will come before Continuous as a comes before o.

So, the sequence is Contain, Contention, Continuation, Continuous, Count, or 3, 2, 1, 4, 5. Hence, the fourth option is correct.