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 I know একটি Independent Clause এবং that he is honest একটি Dependent clause। তাই, এটি Complex Sentence।