The correct answer is Option B: speaks for itself.
The original sentence, "I need not offer any explanation regarding this incident - my behavior is speaking itself," is grammatically incorrect and lacks clarity. It requires correction to convey the intended meaning effectively.
The phrase "speaking itself" in the original sentence is incorrect. Instead, the correct phrase to use is "speaks for itself," which means that the behavior or action is clear and understandable on its own without the need for further explanation.
The corrected sentence would be: "I need not offer any explanation regarding this incident - my behavior speaks for itself." This revised sentence effectively conveys that the speaker's behavior is self-explanatory and does not require any additional clarification.
Options A, C, and D are incorrect because they use different verb tenses or prepositions that do not fit the context or the intended meaning.
Option E, "No correction required," is not the correct answer because the original sentence does require correction to use the appropriate phrase "speaks for itself" instead of "speaking itself."
Therefore, the correct answer is Option B: speaks for itself.