For f(x)=?x and g(x) = 4x+1, find the following composite functions and state the domain of each.(a) fog(b) gof(c) fof(d) gog(a) (fog)(x) = (Simplify your answer.)Select the correct choice below and fill in any answer boxes within your choice.A. The domain of fog is {x}.(Type an inequality. Simplify your answer. Use integers or fractions for any numbers in the expression.)B. The domain of fog is all real numbers.(b) (gof)(x) = (Simplify your answer.)Select the correct choice below and fill in any answer boxes within your choice....A. The domain of g of is {x}.(Type an inequality. Simplify your answer. Use integers or fractions for any numbers in the expression.)B. The domain of g of is all real numbers.(c) (f of)(x) = (Simplify your answer.)Select the correct choice below and fill in any answer boxes within your choice.