Correctly order the steps involved cellular immunity:
1) The Tc recognizes the infected host cell
2) The Tc interacts with epitope presented by MHC-I on the dendritic cell
3) The Tc secretes perforin and granzyme, causing apoptosis
4) The helper T cell activates the Tc cell
A.1,2,4,3
B. 4,2,1,3
C. 2,4,1,3
D. 2,1,3,4