Propaganda may be both positive and negative in viewpoint and effect.
a. true
b. false

If the words "positive" and "negative" here refer to whether propaganda aims to create a positive or negative image, then the answer is :"True".

For example, in Socialist Countries in 1970s a big portion of propaganda was positive, aiming at convincing the citizens that socialism is good for the country. 

Urban growth invariably feeds increased commercialization and industrialization. it requires continually expanding land areas. when urbanization rates are high, and countries do not have the institutional and managerial capacities or economic wherewithal to manage such rapid growths, they exert intense pressure on the types and nature of the resulting settlements. they contribute to the development of overcrowded slums and shanty towns without adequate essential services and necessary infrastructure.-by asit k. biswas and cecilia tortajada