Determine whether the following function is continuous at a. Use the continuity checklist to justify your answer. x²-144 x-12 if x # 12 f(x) = ; a = 12 10 if x = 12 Select all that apply. A. The function is continuous at a = : 12. B. The function is not continuous at a = 12 because f(12) is undefined. C. The function is not continuous at a = 12 because lim f(x) does not exist. X→12 D. The function is not continuous at a = 12 because lim f(x)#f(12). X→12