Read the following passage carefully and answer the questions that follow.
All sources of energy upon which industry depends are wasted when they are employed, and industry is expanding them at a continually increasing rate. Already coal has been largely replaced by oil and oil is being used up so fast that the East and the West alike consider it to be necessary for their prosperity. And what is true of oil is equally true of other natural resources. Everyday, in fact, many miles of forests are turned into newspapers, but there is no known process by which newspapers can be turned into forests. You will say that this need not worry us, since newspapers will be replaced by radio, but radio requires electricity, electricity requires power and power requires raw materials.
According to this passage, the most indispensable item for an industrialised society is

Options

A. the radio
B. raw materials
C. power
D. electricity

Answer

B