Show that for compact operator $\|A_nB-AB\|\rightarrow0$

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Let $A_{(n)}:\mathcal B\rightarrow \mathcal B$ be a linear bounded operators such that for any $f\in \mathcal B$, $A_nf\rightarrow Af$. Show that then for any compact operator $B$

$$\|A_nB-AB\|\rightarrow0$$

Any tips how to show this?