Final answer:
The grammar error in the given sentence is tense disagreement. The verb 'is going' is in the present tense, while the rest of the sentence is in past tense. To correct the error, the sentence could be revised to maintain consistency in the past tense.
Step-by-step explanation:
The grammar error that appears in the given sentence is B. Tense disagreement. In the sentence, the verb 'is going' is in the present tense, while the rest of the sentence is in past tense, as indicated by the past tense verb 'loved' in the first clause. To correct the error, the sentence could be revised to say, 'Maria loved to travel, and no advice about safety was going to keep her from taking a trek across Alaska.' This maintains consistency in the past tense throughout the sentence.