Final answer:
The correct option is b. Remove the comma after "history".
To correct the punctuation error in the sentence, the comma after 'history' should be removed, as it improperly separates items that are not part of a series.
Step-by-step explanation:
The correct change needed to repair the punctuation error in the sentence 'Angie agreed to help Matt repair his car engine, so he promised to tutor her in calculus, history, and work together all weekend.' is option b. Remove the comma after 'history'.
The list of subjects suggests a series, while the phrase 'and work together all weekend' is not part of the series and should not be separated from 'history' with a comma. Instead, it continues the sentence describing the entirety of what Matt promised Angie, so removing the unnecessary comma corrects the punctuation error. This is in line with the rule for serial commas where a comma should be used between items in a series but not before a conjunction like 'and' if it precedes a non-series-related phrase.