To meet growing energy needs in Ibernia, companies built. ..

[Vincen]

To meet growing energy needs in Ibernia, companies built more energy plants that burn
oil, coal, and natural gas. To limit carbon dioxide emissions and encourage the
development of "green" energy, the Ibernian governmental recently imposed a carbon tax
that directly affects the newly built plants. We should therefore expect to see more money
and innovation in the development of alternative energy and a decrease in the country's
reliance on fossil fuels.

Which of the following is an assumption on which the argument depends?

(A) The plants that burn oil, coal, and natural gas can easily be converted so that
they use "green" energy.

(B) The carbon tax will lead to the closure of many of the plants that burn oil, coal,
and natural gas.

(C) Ibernia's energy needs will continue to grow even if the carbon tax results in
higher energy costs.

(D) Ibernia's reliance on fossil fuels is likely to cause the country to fall behind its
neighbors in efforts to develop "green" energy.

(E) The cost of developing alternative energy is less than the cost to existing energy
plants of the government's carbon tax.

The OA is E.

What is the best approach to determine the correct answer?