B. Kristoff worked hard on his diet, but he could not resisted snacking.
Resisted should be resist because it has "could not" in front of it and "could" requires the present tense of the verb.
A. All of the cars in the parking lot today are parked illegally.
Correct because "are" is a present tense verb going with "today."
C. Marcia's lecture on the Ming Dynasty made the front page of the newspaper.
Correct because it happened in the past tense and the past tense of make is "made."
D. Sherel poured herself her third cup of coffee, without apology, and drank it.
Correct because "poured" and "drank" are both past tense verbs so the tense is consistent in the sentence.