Which structures are part of the body's first line of defense against pathogens? a. white blood cellsb. red blood cells c. lymph nodesd. mucous membranes

Mucous  membrane(answer  D)   is  the   structure  part   of  the  body  first  line  of  defense  against   pathogens. The body first   line  of  defense  are  structures ,chemicals  and  processes  that  prevent pathogen  from  entering  the  body .They  are  two  layers  of  mucous  membrane which  are  tightly  packed  to  prevent  entry  of  many pathogens. The  continual  shedding  of  the  cell  carries  away  micro- organism.