Answer: b. it's profitable in the short run for another member to increase production.
Step-by-step explanation:
This refers to an oligopolistic market where there are few producers of a good. These producers can come together to create a cartel that fixes prices for the goods and services they produce.
If they agree to cut back production, this will have the effect of increasing prices due to a reduction in supply. If a member decides to increase production, they would enjoy profits in the short term from the increased prices.
The other members would however respond by increasing production as well so those profits would stop towards the long run.