Which of the Following Is True of Impression Trays

Which of the following is true of impression trays?

A) Stock trays are made of plastic rather than metal and can be solid or perforated.
B) Plastic trays are inexpensive and are disposable, whereas metal trays are more expensive and must be cleaned and sterilized between uses.
C) Custom trays are constructed in the patient's mouth with chemically cured, light-cured, or thermoplastic resins on casts of the teeth.
D) The triple tray is a custom full-arch tray used for bite registration.