Which body system is responsible for protecting the body against infection?
the nervous system
the circulatory system
the immune system
the respiratory system

The immune system

Explanation:

The immune system is a complex network of proteins and cells that defends the body against infection or any invasion. The human defense system in the body is actually made up of entire organs and vessel systems like the lymph vessels. The immune system is made up of organs that control the production and maturation of certain defense cells.

Initially, all living things are subjected to attack from disease causing agents. Even bacteria, so small that more than a million could fit on the head of a pin, have systems to defend against infection by viruses. This kind of protection gets more sophisticated as organisms become more complex.

Respiratory system

Explanation:

took the test got it right.

the  different  of  these  two  are  that  they  differently  handle  their  team.

an  expressive  leader  focuses  on  the  task  at  hand  and  make  sures  that  their  goal  is  achieved.  they  accurately  finish  the  task.  an  instrumental  leader  on  the  other  hand  works  on  the  unity  of  the  group,  they  care  more  about  their  employees.  all  the  while  creating  a  good  environment.