Correct Answer: 3, 2, 6, 7, 5, 1, 4

Solution : Given:
1. Amphibian 2. Ambiguous 3. Ambience 4. Amplify 5. Amorphous 6. Ambivalent 7. Ameliorate

Step 1: Compare the first and second letters of each word. Since all the words start with the same letter A and m , so move on to the next letter.
Step 2: The third letter of each word is b , e , p , or o . Based on the alphabetical order of these letters, we can arrange them – Am b iguous, Am b ience, Am b ivalent, Am e liorate, Am o rphous, Am p hibian, Am p lify.
Step 3: Compare the fifth letter of (Ambi g uous, Ambi e nce, Ambi v alent) and the fourth letter of (Amp h ibian, Amp l ify). Ambience will come before Ambiguous and Ambivalent in the sequence as e comes before g , and v in the alphabetical system. Similarly, Ambiguous will come before Ambivalent as g comes before v in the alphabetical system. Also, Amp h ibian will come before Amp l ify as h comes before l .

So, the sequence is Ambience, Ambiguous, Ambivalent, Ameliorate, Amorphous, Amphibian, Amplify, or 3, 2, 6, 7, 5, 1, 4. Hence, the first option is correct.