Đáp án đúng: C
C4H10.
$\begin{array}{l}{{V}_{C{{O}_{2}}}}\,=\,32,5\,-\,12,5\,=\,20\,c{{m}^{3}};\,{{V}_{{{O}_{2}}\,pu}}\,=\,45\,-\,12,5\,=\,32,5\,c{{m}^{3}}\\\xrightarrow{BT\,O}\,{{V}_{{{H}_{2}}O}}\,=\,2{{V}_{{{O}_{2}}\,pu}}\,-\,2{{V}_{C{{O}_{2}}}}\,=\,25\,c{{m}^{3}}\,>\,{{V}_{C{{O}_{2}}}}\,\Rightarrow \,ankan\end{array}$
Số C =$\displaystyle \frac{{{V}_{C{{O}_{2}}}}}{{{V}_{X}}}$ = 4 ⟹ C4H10