During the second punic war, the carthaginian general hannibal:

a. brought his entire army, including elephants, over the alps.
b. was defeated by roman armies at the battle of tours in france.
c. became the last foreign invader to fight on rome’s home territories.
d. defeated the roman general maxentius at the battle of the milvian bridge in rome.

The correct answer is letter A.

Explanation: After having their forces slaughtered by the Romans, the leaders of the Carthaginian empire decided to reinforce their war contingent by promoting the mining of the Iberian Peninsula. Concerned about the relentless military reaction of the Carthaginians, the Romans attempted to send a diplomatic mission that should claim to limit the influence of the Carthaginians in that region. By Carthage's refusal, the Romans were ready to battle.

The direct method and indirect method. The direct method is more hands-on with each person within the population and allows factual evidence to come forth primarily from reliable statistics registries/censuses. The indirect method uses responses from only a portion of the population to inquire data about the entire group. (This is a common technique for countries who are still developing.)
Source: http://www.wisegeek.org/what-is-demography.htm