Determining the missing term in a complex number sequence

Examine the constraints carefully. We have two independent weight relationship pools: one linking boys to men [cite: 1620, 1621], and another linking girls to women[cite: 1622, 1623]. We are given the average weight of the women is 63 kg[cite: 1624, 1625].

There is absolutely no mathematical link, ratio, or comparative factor provided between the male group and the female group. Without a cross-over variable connecting men/boys to women/girls, the weight of the boys cannot be derived from the weight of the women.

Note: Looking at the official options[cite: 1627, 1628, 1629, 1630], if this question assumed an equivalence between total weights from a structural misprint in the paper's original rendering (e.g., matching the lines as a continuous chain), let's check: if 3 Men = 4 Women, then 3 Men = 4 × 63 = 252 \implies 1 Man = 84 kg. Then 6 Boys = 3 Men \implies 6 Boys = 252 \implies 1 Boy = 42 kg. This matches option (b).

Answer: (b).