Sea $f(x) = \lim_{h \to 0} \frac{(\sin(x+h))^{\ln(x+h)} - (\sin x)^{\ln x}}{h}$. Entonces $f\left( \frac{\pi}{2} \right)$ es:

a. igual a 0 \\
b. igual a 1 \\
c. $\ln \frac{\pi}{2}$ \\
d. no-existente