Among the following functions, for which one is g(x − y) = g(x) − g(y) for all values of x and y in the domain of y?
(A)g(a)= a^{4}
(B) g(a)= a-7
(C)g(a)=sqrt{a+3}
(D) g(a)={4}/{a-4}
(E) g(a)=7a
(A)g(a)= a^{4}
(B) g(a)= a-7
(C)g(a)=sqrt{a+3}
(D) g(a)={4}/{a-4}
(E) g(a)=7a