Multi-select problem: How does the next paragraph end?

How to slow cook ribs
Prepare the ribs for the grill by trimming away any visual fat and then applying your favorite rub, or just season them with salt and pepper.
Prepare the propane grill by turning it on and letting it heat up, or by lighting a charcoal grill and then letting it heat until the coals begin to turn grey.
Place the ribs on the grill.

Available options: a). Grilled ribs need to be cooked low and slow. If using a gas grill, place the ribs on the grill, turn the heat down to low, and cook them covered for 30 minutes without looking at them. b). Tamp them to a shape of approximately 3 inches (7.6 cm) on each side. This ensures that neither the top of the ribs nor ribs touch during the cooking process. c). Sear the trimmings, if use, till they are golden brown. Remove the ribs, taking care not to let them flip over, or be charred by the smoke. d). Any legs that have been cut off will make decent charred ribs. Turn the ribs slowly to make sure there are no bulging or wasted legs.
a).