Which of the Following Statements Are True of Mucous Membranes

Which of the following statements are true of mucous membranes? (Read carefully and select all of the correct statements.)

A) The urinary bladder is lined with mucous membrane.
B) The mucus produced in the upper respiratory tract helps trap bacteria.
C) Mucus is an important lubricant in the respiratory tract.
D) A mucous membrane may be a lining or a covering.
E) The organ systems with mucous membranes all open into one another.
F) The male urethra has a mucous membrane, but the female urethra has a serous membrane.