While pruning your roses, you get scratched by a thorn. A few days later, you notice that the scratch is filled with yellowish pus. What is this pus?

A)Neutrophils and macrophages that die after consuming their fill of the bacteria that entered your wound.
B)Living bacteria that have been successful in avoiding your immune system.
C)Dead self cells and bacterial waste products.
D)Concentrated prostaglandins produced by injured tissue cells.