a positive effect of urbanization was the building of which public transportation systems?\no taxis\no…

Brief Explanations:

Urbanization led to the development of various public - transportation systems. Trolleys were an early public - transit option that emerged as a positive result of urbanization, providing an efficient way to move people within cities. Taxis are not a public transportation system in the traditional sense as they are for individual or small - group hire. Buses and trains also developed due to urbanization, but trolleys were among the early and significant public transportation systems built during urbanization.

Answer:

B. trolleys