The answer is A)Crucial to all life
A converging lens focuses the diverging, or blurred, light rays from a distant object by refracting (bending) the rays twice. ... This double bending causes the rays to converge at a focal point behind the lens so that a sharper image can be seen or photographed.
(Thus making the vision clear)
Answer:
When people get vaccinated they there will be less change of transfer of communicable diseases