Why is the lysosomal degradation step crucial in the MHC class 2 antigen presentation pathway?

It prevents the activation of cytotoxic T cells.

It allows intracellular pathogens to be processed for MHC class 1 presentation.

It facilitates the transport of peptides into the endoplasmic reticulum.

It ensures that extracellular pathogens are broken down into peptides that can be presented by MHC class 2.