Earth Science c/o crayfish

Question

there are over 400 speciies of crayfish in North America.  One specie, the Virile crayfish, has slowly expanded fromt he east coast to the waters of Montana.  There it encounters the Calico crayfish, whose numbers are now decling.  This is an example of

 

a.  intraspecific competion

b.  interspecific competition

c.  commenslism

d.  mutualism

e.  none of these

 

thanks

Answer 1

a