Final answer:
The pathogen that lives within host tissue with intimate intracellular contact with plant cells is called biotrophic pathogens. OPTION A IS ANSWER
Step-by-step explanation:
The pathogen that lives within host tissue with intimate intracellular contact with plant cells, despite the plant remaining alive, is called biotrophic pathogens. Biotrophic pathogens are obligate biotrophic parasites, meaning they can only survive on a living host but do eventually kill substantial parts or all of their host.
They enter the host plants through stomata, wounds, and the cuticle, and produce haustoria that penetrate the plant cell wall and interact with the host cell membrane. These pathogens, including certain fungi and oomycetes, establish a parasitic relationship where they draw nutrients from living plant cells OPTION A IS ANSWER