The difference between senescence and crisis is that

(a) senescence prevents complete telomere erosion, crisis is the result of complete telomere erosion.
(b) senescence requires p53 and rb, crisis does not.
(c) cells that emerge following crisis have higher levels of telomerase activity than cells in senescence.
(d) in senescent cells, the genome is stable and normal. cells in crisis have undergone a catastrophic breakdown of genomic integrity
(e) all of the above are true.