$V_{dd ruou}=100 lit\Rightarrow V_{C_2H_5OH}=60 lit\Rightarrow m_{C_2H_5OH}=0,8.60.1000=48000 gam$$(C_6H_{10}O_5)_n\rightarrow nC_6H_{12}O_6\rightarrow 2nC_2H_5OH$
$162n \overset{h=90\%}{\rightarrow} 92n$
$m_{(C_6H_{10}O_5)_n} 48000$
$m_{(C_6H_{10}O_5)_n}=\frac{48000.162n}{92n}\Rightarrow m_{khoai}=\frac{100.m_{(C_6H_{10}O_5)_n}}{25}\approx 338087 gam$
$\Rightarrow m\approx 338,09 kg\Rightarrow Chon:B$