Evidence of bias in the declaration of sentiments

What would lead a historian to consider two events to have a relationship of correlation rather than causation

Which statement can be said to be true after examining this map? (1 point) christianity remained popular in egypt after 400 ad. christianity was the only religion in the roman empire until 476 ad. christianity expanded in the roman empire after 325 ad. christianity did not expand beyond the boundaries of the roman empire by 476 ad

What factor aided the russians in defeating napoleon's troops?