Production possibilities frontiers are usually bowed outward. This is because a. resources are specialized; that is, some are better at producing particular goods rather than other goods. b. of the effects of technological change. c. the opportunity cost of producing a good decreases as more and more of that good is produced. d. the more resources a society uses to produce one good, the fewer resources it has available to produce another good.

d. the more resources a society uses to produce one good, the fewer resources it has available to produce another good.

Explanation:

The Production possibilities frontiers is a curve that shows the various combination of two goods a company can produce when all of its resources are fully utilised.

As more quantities of a product is produced, the fewer resources it has available to produce another good. As a result less of the other product would be produced. So, the opportunity cost of producing a good increases as more and more of that good is produced.

Please check the attached image for a diagram of the Production possibilities frontiers

answer; /// i believe the correct answers are (b) change in population and (e) future expectation of check first, good luck

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.'