You should have gratitude__Sumon for his help

A to

B with

C on

D of

Correct Answer: Option A

Gratitude to/for = কৃতজ্ঞতা
You should have gratitude to Sumon for his help=সুমনের সাহায্যের জন্য আপনার কৃতজ্ঞতা থাকা উচিত