Answer:
b. Alternatives to nonrenewable energy sources can be as effective.
Step-by-step explanation:
Sources of energy can either be renewable or nonrenewable. Nonrenewable sources of energy e.g petroleum, coal etc are those that are used faster than can be replenished. They tend to release pollution into the environment.
On the other hand, renewable sources of energy has been employed in order to reduce the debilitating effect caused by the nonrenewable sources. Renewable sources of energy, which include solar, wind etc are being technologically used to produce energy. They have proven effective in the sense that they generate energy in an eco-friendly manner. This is the reason they are called Green or clean energy.
Renewable sources are found to be effective and eco-friendly alternatives to the nonrenewable sources.