Which statement about paragraphs is accurate? a. they always contain a topic sentence. b. they are always the same length. c. they are always focused on a main idea. d. they are always indented.

The correct answer is C. they are always focused on a main idea. They don't have to be indented as that depends on the formation style. They don't have to contain a topic sentence if the author is skilled and experienced enough to omit it and still make a good paragraph. They're most definitely not always the same length and can vary, but are usually similar.