If a Plant Produces Alkaloids, How Will Ingesting These Compounds

If a plant produces alkaloids, how will ingesting these compounds affect an herbivore?

A) The herbivore would be unable to digest certain proteins.
B) The herbivore's enzymes would be unable to function.
C) Unusable amino acids would be incorporated into the herbivore's proteins.
D) The herbivore's nervous system would be damaged.
E) The herbivore's jaws would become stuck together.