For Each Feature of Self-Tolerance Described in Questions ,Choose the Term

Multiple Choice

For each feature of self-tolerance described in questions ,choose the term (letters A-K) that most closely matches it.
-Mechanism of central tolerance of B cells

A) Immature (IgM+IgD-)
B) Thymic cortex
C) Bone marrow
D) Antigen recognition without T cell help
E) Receptor editing
F) Activation-induced cell death
G) Regulatory T cell-mediated suppression
H) Antigen recognition with costimulation
I) Double positive (CD4+CD8+)
J) Anergy
K) Thymic medulla