The dairy industry still uses cow's milk as the base for its varied products. Over time, however, competition from other types of milk has forced changes in the traditional American taste for milk, ice cream, cheese, cottage cheese, yogurt, frozen yogurt, and sherbet. Currently, for example, soy milk and other related items are making inroads in this traditional market. has driven the dairy industry to reduce milk fat content from whole milk to 2% to 1% to no-fat over the last few decades.

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.'

b is the correct answer