Hydrocarbons can be widespread in sedimentary rock, but reservoirs are formed by: select one: a. porous and permeable beds bounded on all sides by impermeable rock. b. large cavities, such as cave systems in limestone reefs. c. structural traps. d. porous and permeable beds bounded on all sides by impermeable rock and large cavities, such as cave systems in limestone reefs. e. porous and permeable beds bounded on all sides by impermeable rock, structural traps, and large cavities, such as cave systems in limestone reefs.