If a chemist performed an experiment in spain, how could she be sure that chemists in china could interpret the measurements she obtained

The answer for #3 is c but i don't know why

Predict the products butane (c4h10) + oxygen —>

Ethanol (c2h5oh) is produced from the fermentation of sucrose in the presence of enzymes. c12h22o11(aq) + h2o(g) 4 c2h5oh(l) + 4 co2(g) determine the theoretical yield and the percent yields of ethanol if 680. g sucrose undergoes fermentation and 326.5 g ethanol is obtained. theoretical _ g _ percent %