Read the following excerpt from a student essay. How can the writer best improve his or her grammar and mechanics?
Found in the icy waters of the Arctic Ocean the narwhal is a species of whale with a long tusk. Generally, only males have tusks but occasionally females may develop them. The tusks grow up to nine feet long and weigh more than twenty pounds. Researchers aren't exactly sure why narwhals grow these tusks. They might be used to fight other males, to impress females or to help the creatures detect changes in their environment.
A. by fixing misplaced modifiers
B. by fixing run-on sentences
C. by adding missing commas
Select the correct answer from the provided options and reply with the letter associated with it.

C