The answer to your question is B.
Answer:
The crop failures were caused by late blight, a disease that destroys both the leaves and the edible roots, or tubers, of the potato plant. The causative agent of late blight is the water mold Phytophthora infestans. The Irish famine was the worst to occur in Europe in the 19th century.
By siltation, as part of the bed load
The two most obvious ones are on the far right, and near the far left. Oceanic lithosphere is descending into the earth's mantle at these places, and being destroyed. ... At convergent boundaries oceanic lithosphere is always destroyed by descending into a subduction zone
