Si $y = \tan^{-1} \left( \frac{\log(e/x^2)}{\log(ex^2)} \right) + \tan^{-1} \left( \frac{3 + 2\log x}{1 - 6\log x} \right)$, entonces $\frac{d^2y}{dx^2}$ es:

1. [a.] $2$
2. [b.] $1$
3. [c.] $0$
4. [d.] $-1$