If `f(x)=x^2`, `g(x)=\tanx` and `h(x)=\logx`, then value of `(h \circ (g \circ f))(\sqrt{\frac{\pi}{4}})` is -- (a) `0`, (b) `1`, (c) `\frac{1}{\pi}`, (d) `1/2\log\frac{\pi}{4}`