The difference between vertical and horizontal transmission of plant viruses is that vertical transmission ________.

A) transfers viruses from a parent plant to its progeny, and horizontal transmission transfers viruses from one plant to another plant
B) spreads viruses from upper leaves to lower leaves of the plant, and horizontal transmission spreads viruses among leaves at the same general level
C) spreads viruses from trees and tall plants to bushes and other smaller plants, and horizontal transmission spreads viruses among plants of similar size
D) transfers DNA from a plant of one species to a plant of a different species, and horizontal transmission spreads viruses among plants of the same species