Suppose over the last year that the price of iron ore increased from $1,200 a ton to $1,275 a ton. over the same time a measure of the overall price level increased from 150 to 156. the price of iron ore increased by a. more than inflation, so it became more scarce. b. less than inflation, so it became less scarce. c. less than inflation, so it became more scarce. d. more than inflation, so it became less scarce.

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.'