Answer:
Option A
Explanation:
We have,
$\lim_{y \rightarrow1}\left(\frac{1}{y^{2}-1}-\frac{2}{y^{4}-1}\right)=$
$=\lim_{y \rightarrow 1}\left(\frac{y^{2}+1-2}{y^{4}-1}\right)$
$=\lim_{y \rightarrow 1}\left(\frac{y^{2}-1}{(y^{2}-1)(y^{2}+1)}\right)$
$=\lim_{y \rightarrow 1}\frac{1}{y^{2}+1}=\frac{1}{1+1}=\frac{1}{2}$
