The economic growth model predicts that the
a. level of per capita gdp in poor countries will decrease over time and the poor nations will not be able to catch up with the rich nations.
b. level of per capita gdp in poor countries will increase faster than rich countries and the poor nations will catch up with the rich nations.
c. rich countries will have stagnant growth and will catch up with the poor countries, so that there will be a convergence toward a "poverty trap."
d. level of per capita gdp in rich countries will increase so fast that it will be difficult for poor countries with low income per capita to ever catch up with the rich countries

The correct answer is D. level of per capita GDP in rich countries will increase so fast that it will be difficult for poor countries with low income per capita to ever catch up with the rich countries .

Explanation:

Robert Solow's economic model, also known as the exogenous growth model, states that the growth of an economy should be based on the management of supply, productivity and investment, and not on the exclusive result of demand.

In the literature we can find information about this theory under the name of “neoclassical growth model”, a name that may be strange if we do not briefly study the roots that fed this model, but that has a simple explanation.

Through the analysis of Harrod's model from the perspective of the “neoclassical school,” the author made several modifications that would gradually formulate a new theoretical construct. In this way, while for Harrod the variations in demand were the fundamental objects to study, they lost all their prominence in Solow's theory.

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.'