Which of the following is NOT true?

The days of the week are only capitalized at the beginning of a sentence
Proper nouns must always be capitalized
Proper nouns must always be capitalized Periods and events should be capitalized (i.e. the Great Depression)
The first word of a sentence should always be capitalized (even inside quotation marks) The first word of a sentence should always be capitalized (even inside quotation marks)

Periods and events should be capitalized (i.e. the Great Depression)