Find the error in this passage, and then identify what type of error it is.
Basic hygiene includes washing your hands after using the bathroom. However, many people neglect this simple practice. Behavioral psychologists have conducted studies that included counting how many people washed their hands in a public restroom. They were surprised to find that most people does not wash their hands.
A - Grammar
B - Consistency of tone
C - Spelling
D - Punctuation