Which of the following organisms start the carbon cycle?

Which statement about plant classification below is true? a. all vascular plants are angiosperms, but not all nonvascular plants are mosses. b. no nonvascular plants bear seeds, but not all vascular plants bear seeds c. not all nonvascular plants bear seeds, but all vascular plants do bear seeds. d. not all angiosperms produce flowers, but all gymnosperms produce cones.