Why malarial concepts called hypothesis?

When Charles Louis Alphonse Laveran discovered that malaria was caused by a protozoan parasite in 1880, the miasma theory began to subside. ... In the early 1890s Manson himself began to formulate the complete hypothesis, which he eventually called the mosquito-malaria theory.

c. is the correct answer

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.