Most vaccines protect only against pathogens that fall within a certain region of antigenic space. Suppose that a vaccine protects against any strain falling within a sphere of radius 2 centered at thepoint (2,1,0) in antigenic space. For each strain, determine whether this vaccine will be effective.(a) A strain located at (0,0,0) in antigenic space(b) A strain located at (1,0,3) in antigenic space(c) A strain located at (1,0,1) in antigenic space(d) A strain located at (1/4,2,1) in antigenic space