In older posts, you have indicated that your top choice college is BC. If that is still the case then definitely take Latin IV. Per BC’s website, “We recommend that students pursue four years of coursework in English, social science, mathematics, foreign language, and laboratory science.” A school like BC is highly competitive and not having the recommended coursework could put your application at a disadvantage – many highly qualified applicants will be sure to fulfill the recommendations. http://www.bc.edu/admission/undergrad/process/freshman.html