Which of the following is NOT a means of generating diversity in the variable regions of the T cell receptor genes?
| Cleavage at the coding-heptamer RSS junction by RAG-1/2 |
| Somatic hypermutation following activation |
| Hairpin cleavage by Artemis to generate P nucleotides |
| Addition of N nucleotides by TdT |
| All of the above generate diversity in the variable regions of the T-cell receptor genes. |