Which of the following statements best reflects the underlying tone of…

Only an educated population can best make use of the benefits of economic progress.
All economic development should be aimed at the creation of leisure.
An increase in the educated population of a country leads to an increase in the happiness of its people.
Use of machines should be encouraged in order to create a large leisured population.

Answer

Only an educated population can best make use of the benefits of economic progress.

(a) On re-examination, this is the best fit if the passage argues that the gains of economic progress become meaningful only when people are sufficiently educated to use leisure and opportunities well. Verdict: Correct.
(b) This is too absolute: the passage may value leisure, but it need not say that all economic development should be aimed only at creating leisure. Verdict: Incorrect.
(c) This adds a direct claim about education causing happiness, which is stronger and narrower than the likely tone of the passage. Verdict: Incorrect.
(d) This shifts the focus to machines as the solution; the underlying tone is about human capacity to benefit from progress, not merely mechanization. Verdict: Incorrect.