Residents of poor countries tend to have higher rates of infant mortality because:

They have lower GDP rates which do not allow them to invest more in health care.

Explanation:

Countries that are poor economically have higher infant mortality rates than the countries which are developed and economically rich. Countries like Somalia, Afghanistan, Central African Republic are poor countries and their GDP is very less than developing and developed countries so they invest less in the health care sector compared to developing and developed countries.

Due to this reason, the health care system is poor in these countries and the infant mortality rate is very high. For example in 2018 the infant mortality rate of Afghanistan was 110.6 and Afghanistan was at first position in infant mortality rate.

answer; (b) medicare fee schedule;

                                                        water

a colorless, transparent, odorless, tasteless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.

                                                        halon  

any of a number of unreactive gaseous compounds of carbon with bromine and other halogens, used in fire extinguishers, but now known to damage the ozone layer.

                                                  dry chemical

extinguishing agent used on class a, class b, and class c fires.

                                                  carbon dioxide

a colorless, odorless gas produced by burning carbon and organic compounds and by respiration. it is naturally present in air (about 0.03 percent) and is absorbed by plants in photosynthesis.