Answer:
Option c (No, T cells left from the previous infection can kill any virus.
)
Explanation:
When ever viral infection occur, body's immune system start to fight against it by activating B-cells and T-cells.
B-cells produce antibodies that bind with virus and act as label. This label indicate virus as foreign substance. Hence T-cells recognize it and kill it. Furthermore, B-cells form memory cell that keep the viral memory. if this viral infection occur again in future, T-cell recognize it and eliminate the virus.This mechanism is called immunity.
