Select the correct sentence.

Bargain on/for something:
English Meaning - To expect or be prepared for something.
Bangla Meaning - প্রত্যাশা করা; প্রস্তুত থাকা। 
Example - 
1. We did not bargain for your taking this initiative.
2. We hadn't bargained on such a long wait.
3. The strength of opposition to the project was more than she'd bargained for.

এছাড়াও, 
Bargain over something - কোনো কিছুর জন্য দরকষাকষি করা। 
Bargain away - বিকিয়ে দেওয়া।

So, Correct Sentence - His response to the criticism was more than the author had bargained for.

Source: 
1. Cambridge Dictionary. 
2. Accessible Dictionary by Bangla Academy.