The first one is B because it is just stating the facts
I think the correct answer would be A. The infinitive is the most versatile verb form because it can be used as a verb, noun, adjective and even an adverb. An infinitive verb is classified as a non-finite verb wherein it could be used as the principal verb in a sentence. The infinitive verb form of a verb is commonly preceded by the word "to". For instance: to run, to dance, to swim, to sleep etc. An example of an infinitive verb as a noun is: To swim a mile is her greatest dream. The infinitive form of the verb is "to swim"
A thesis statement is found in the first paragraph. It generally has a list of three things, though it can be more, that are the main topics you'll be discussing in your essay.
For example, "Tigers are the best of the big cats because of their loud voices, bright coloring, and social structure."