Which of these is a weakened or dead form of a pathogen that causes an immune response?

Vaccination is a way to trigger the immune response. Small doses of antigen such as a dead or weakened live virus are given to activate immune system “memory”. Memory allows your body to react quickly and effectively to future exposures.

Vaccine

Explanation: there's no point, I won't be the type of person who says "A vAcCiNe Is a ShOt no I won't waste your time by being that person

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.