What system is responsible for defending the body against harmful substances? a. circulatory system b. musclar system c. endocrine system d. immune system

The right option is; d. Immune system

The immune system is responsible for defending the body against harmful substances.

The immune system is the body’s defense system that protects the body against infectious pathogens and other invaders. The immune system is composed of many biological structures (special cells, proteins, tissues, and organs) and processes that functions together to protect the body. White blood cells are one of the important cells of the immune system that destroy harmful substances or disease-causing organisms that invade body systems.

hello my name is kailey,

i think the answer is false i   hope this

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.