Answer:
B ) "Many people are disappointed in ethanol because they believed that it would help reduce the price at the pump, not increase it."
Step-by-step explanation:
The question wants to know which statement implies that the main supporters of ethanol have changed their mind about their previously supported issue. Considering the four options given in the question, the right answer will be the second option.
First option did not mention anything about the supporters, but rather include only about the prices and cost of fuels.
Second option correctly mentioned the changed mindset of the ethanol supporters in their previous notion about the use of ethanol. It states that they are disappointed as they believed that it will help in the reduction of fuel prices and not increase it.
Option 3 mentions the supporters but did not say anything about their changed opinion, but rather states that they chose to ignore the serious drawbacks of its use.
The last option did not even mention anything about the supporters or their reversed decision. It rather included the "overenthusiastic supporters" considering all sides of the issue. It gives a proposed solution and idea of how to deal with the issue.
Thus, the correct answer is option B.