Explanation

(c)
Thermite is the mixture of $Fe_{2}O_{3}$ and $Al$. Due to great affinity of aluminium towards oxygen, it readily combines with oxygen. Hence, Goldshmidt used Al to reduce metal oxides in extraction. In thermite, the ratio of $Fe_{2}O_{3}$ and Al is taken 3:1 by weight.
$Fe_{2}O_{3} + 2Al \rightarrow 2Fe + Al_{2}O_{3}$
($2 \times 56 + 3 \times 16 = 160$) $(2 \times 27 = 54)$