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Which of the following best explains how the discovery of oil at Spindletop helped change Texas from a rural to an urban state?

A)Oil companies built railroads to carry workers from out of state.

B)The country's need for Texas oll led to an increase in government grants.

C) The discovery of oil made Texas the new home of the successful automobile industry.

D) The growth of oil companies into other industries led to an increase of jobs.