How Do Self-Antigens That Are Specific to Tissues Away from the Thymus

Multiple Choice

How do self-antigens that are specific to tissues away from the thymus (like insulin or keratin for example) get in the thymus so that developing T cells that react to them can be deleted?

A) Dendritic cells pick them up in the periphery and carry them to the thymus.
B) Specialized macrophages in the thymus filter the bloodstream and present antigens found there to developing T cells.
C) A transcription factor, AIRE, is expressed in thymic medullary epithelial cells, which allows these cells to express proteins normally found in other tissues.
D) They do not get to the thymus, all tissue-specific T cells are deleted in the periphery.
E) There are special chaperone proteins that bind to peripheral proteins and carry them to the thymus.