Liquidity refers to a. the ease with which an asset is converted to the medium of exchange. b. the measurement of the intrinsic value of commodity money. c. the measurement of the durability of a good. d. how many time a dollar circulates in a given year.

a. the ease with which an asset is converted to the medium of exchange

Explanation:

Liquidity measures how quick an asset can be converted to cash.

Money, cash is the most liquid asset. This is why it can be easily used as a medium of exchange.

Real estate is considered illiquid because it cannot be easily converted to cash.

Stocks are relatively liquid because they can be quite easily converted to cash.

Velocity measures how many times a dollar circulates in a given year.

Money can be used to measure the intrinsic value of a commodity.

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.'