Final answer:
The true statements about block quotes are that they are indented, do not require quotation marks, and do not need an author mention in the main text, but the page number in the in-text citation comes after the period.
Step-by-step explanation:
When addressing the question of what is true about block quotes, the following points are accurate:
The entire block quote is indented from the main body of text, typically by 0.5 inches.
Block quotes can be used regardless of whether the author's name is mentioned in the text; their purpose is to present a long quotation clearly.
The page number at the end of a block quote is placed after the period, within the parentheses of the citation.
Quotation marks are not used around block quotes, as the indentation itself indicates that the text is a direct quotation.
Therefore, considering these points, the correct answer is that the entire block quote is indented, quotation marks are not used, and while the author's mention is not a requirement for using block quotes, the page number in the citation does indeed come after the period.