Answer:
A. loss of current sales due to a new project being implemented.
Step-by-step explanation:
In business, erosion takes place when a new product or project competes with another product or project from the came company. This "internal" competition reduces the revenues and benefits from existing products or projects. It is basically a form of business cannibalization, where the left arm takes away from the right arm. E.g. newer smartphone models decrease the sales revenue from existing (older) models.