I understand the answer is D) 1 % a month, but i don't understand why you don't use the formula

EAR = (1+(APR/m)^(m)-1; with m = number of compounds per year

If someone could explain i would appreciate it

Which of the following accounts has the highest EAR? A) one that pays 9.6% per year B) one that pays 5.4% every six months C) one that pays 2.4% every three months D) one that pays 1.0% per month