A firm's consist of expenditures that must be made before production starts that typically, over the short run, , regardless of the level of production.

A. Fixed costs ;do not change

B. Variable cost ;are constantly changing

C. Fixed cost ;are consistently changing

D. Variable cost ;do not change

A. Fixed costs ;do not change

Explanation:

Fixed costs refer to costs that remain fixed over a period of time and do not change with change in production level as opposed to variable costs that change with change in production. An example as rent that is paid for a factory building for the purpose of producing cell phones. Here increase in production of cell phones do not alter the rent cost paid over a period of time say one or two years.

c

explanation: because you need to reduce the pollution on land,the exhaust fumes will stop,and stop it in water,the oil that is in the oceanharms the fish   sorry if you   have been waiting long  

answer; correlational;