response/answer/reply

[Silverobama]

Hi,

Everyone agrees that there are simply too many cars on road but who will be the first to stop using theirs? Although everyone hates being stuck in traffic, no one sees their cars as part of the growing problem. However, with traffic growth of up to 84 percent expected by 2031 and the ever-increadsing cost of accidents and delays already at $160bn in Europe, there is a growing need to change our "car culture" and develop alternative forms of transport as quickly as possible.
One ____ is to make cars more expensive by increasing taxes on petrol. However, tax increases will affect the people who live in the country more than city drivers and do little to reduce inner-city drivers and do little to reduce inner-city traffic.

There are three choices for the blank:

response/reply/answer

Which one is correct? I chose "response" but the answer is not that one.

[billmcd]

Hi,

Everyone agrees that there are simply too many cars on road but who will be the first to stop using theirs? Although everyone hates being stuck in traffic, no one sees their cars as part of the growing problem. However, with traffic growth of up to 84 percent expected by 2031 and the ever-increadsing cost of accidents and delays already at $160bn in Europe, there is a growing need to change our "car culture" and develop alternative forms of transport as quickly as possible.
One ____ is to make cars more expensive by increasing taxes on petrol. However, tax increases will affect the people who live in the country more than city drivers and do little to reduce inner-city drivers and do little to reduce inner-city traffic.

There are three choices for the blank:

response/reply/answer

Which one is correct? I chose "response" but the answer is not that one.

Because the text identifies the issue as a "growing problem", I suspect that the "correct" answer should be "answer".