Which Statement Is Correct About the Frame Relay Technology

Which statement is correct about the Frame Relay technology?

A) It uses switched virtual circuits for data delivery.
B) It is a technology designed for the leased line WAN service.
C) It comes with an error discovery and recover function during packet delivery.
D) Its frames have a high overhead and thus slow in the delivery of WAN frames.
E) It is much used for "both" data and voice services.