Amanda buys a ruby for $330 for which she was willing to pay $340. The minimum acceptable price to the seller, Tony, was $140. Amanda experiences: a. a producer surplus of $200, and Tony experiences a consumer surplus of $10.
b. a consumer surplus of $10, and Tony experiences a producer surplus of $190.
c. a consumer surplus of $670, and Tony experiences a producer surplus of $200.
d. a producer surplus of $10, and Tony experiences a consumer surplus of $190.

a consumer surplus of $10 and Tony a producer surplus of $190

Explanation:

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'