Let f and g be two differential functions on R such that $\;f^{'}(x) > 0\;$ and $\;g^{'}(x) > 0\;$ for all $\; x \in R\;$. Then for all x :

Question

$(a)\; \normalsize f(g(x)) > \normalsize f(g(x-1)) \qquad(b)\; \normalsize f(g(x)) > \normalsize f(g(x+1))\qquad(c)\;g(f(x)) > g(f(x-1))\qquad(d)\;g(f(x)) > g(f(x+1))$