Which sentence correctly follows the rules for mla in-text citations for a quote from page 9 of john smith's book, solving equations?
a. according to john smith, the most common error in solving math questions "relates to the order of operations" (9).
b. according to john smith, the most common error in solving math questions "relates to the order of operations" (9.)
c. according to john smith, the most common error in solving math questions "relates to the order of operations (9)."
d. according to john smith, the most common error in solving math questions "relates to the order of operations (9.)"