State which of the transaction/s listed below will or will not be counted in the Gross Domestic Product. A meat processing company builds a new plant.
A drug dealer sells $5000 worth of illegal drugs.
Purchase of a used car.
A clothing factory produces one million worth of dress shirts.
A merchant sells United States currency on the black market.

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.'