Please Identify What Type of Error the Following Sentence Includes

Please identify what type of error the following sentence includes: He spoke with a heavy german accent, but I could understand him.

A) Capitalization
B) Punctuation other than commas or semicolons (including hyphens and apostrophes)
C) Commas or semicolons
D) Number expression (word or figure form)
E) Symbols (including dollar and percent signs)