Please explain in a proper way with using graph elasticity and pricing ?and by asuming values

A city has built a bridge over a river and it decides to charge atoll to everyone who crosses. For one year, the city charges a variety of different tolls and records information on how many drivers cross the bridge. The city thus gathers information about the elasticity of demand. If the city wishes to raise as much revenue as possible from the tolls, where will the city decide to charge atoll: in the inelastic portion of the demand curve. the elastic portion of the demand curve. orthe unit elastic portion? Explain. Hint: the relationship between revenue and elasticity of demand. ( Read the textbook of section 5.3: Elasticity and pricing, and the Netilix case on Page 24 in Slide W4)