If a good with a positive externality was provided by the market then B. less than the efficient amount of the good would be traded.
Why would less than the efficient amount be traded?
A good with a positive externality would benefit a third party which means it would benefit more than those people who bought it.
As a result, it would be traded at an amount which is less than the efficient amount because the effect would be as though an efficient amount was traded.
In conclusion, option B is correct.
Find out more on positive externality at https://brainly.com/question/477170.
