The value of the cpi's "market basket" is determined by

The value of the CPI’s “Market Basket” is only determined by or through consumer survey. The consumer survey is the survey given by the producer to its consumers in means of finding out the quality of their products or services in which whether they are appealing or unappealing to their consumers and a way of having to find out where they lack or at their best. 

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.'