Which one is a complex sentence?

A complex sentence is a sentence with one independent clause and at least one dependent clause. It works best when you need to provide more information to explain or modify your sentence's main point.
আমরা দেখতে পাচ্ছি যে, অপশন B-তে You know একটি Independent Clause এবং that I am straightforward একটি Dependent clause। তাই, এটি Complex Sentence।