Consider the following statements: At the present level of technology available in India, solar energy can be conveniently used to I. supply hot water to residential buildings. II. supply water for minor irrigation projects. III. provide street lighting. IV. electrify a cluster of villages and small towns. Of these statements

The correct answer is C because of the practical limitations of solar technology at the time this question was framed and the scale required for certain tasks. Statement I is correct as solar thermal systems for hot water are simple and widely used in homes. Statement II is incorrect because although solar pumps exist for individual farms, supplying water for an entire minor irrigation project requires massive, consistent power that was not considered conveniently available at a large scale. Statement III is correct as solar photovoltaic cells are highly efficient and common for localized street lighting. Statement IV is incorrect because electrifying entire clusters of villages and small towns requires a centralized grid or massive storage capacity that was not technologically or economically convenient at the time. Therefore, while small scale applications in I and III are convenient, the large scale infrastructure required for II and IV makes them incorrect in this context.