Solution

Argentite will give $$Ag$$ as:
$$Ag_2S\rightarrow 2Ag$$
Molecular wt of $$Ag_2S=248\ g$$ and $$Ag=108\ g$$
Therefore $$248\ g$$ of $$Ag_2S$$ gives $$2\times 108=216\ g$$ of $$Ag$$
Amount of $$Ag_2S$$ required to obtain $$1\ g\ Ag$$ is:
$$248/216\ g=1.148\ g\ Ag_2S$$
Given that $$1.34\ g\ Ag_2S$$ is obtained from $$100\ g$$ ore.
Therefore for $$1.148\ g\ Ag_2S$$, amount of ore required is:
$$=\frac {100\times 1.148}{1.34}\ g$$=$$85.67\ g$$
Thus option B is correct.