According to the peripheral model, an urban area consists of an inner-city surrounded by _________. 
 a. large industrial parks far removed from any residential neighborhoods. 
 b. large suburban residential and business areas tied together by a beltway or ring road. 
 c. a beltway of connected roads all leading to small rural areas where the rich life. 
 d. small clusters of suburban malls and run-down shanties (shacks).