Is there a formal ranking of importance of grammatical errors? it is obvious that some mistakes are are more important than others, so more info on this matter would be very useful.

Select the sentence that has no punctuation or capitalization errors. a.this semester, i'm taking math, history, german, and english. b.this semester, i'm taking math, history german and, english. c.this semester, i'm taking math history, german and english. d.this semester, i'm taking math, history, german, and english.