Respuesta :
Diaz was a military general and his military prowess helped him advance against the previous regime in Mexico, but he was formally elected as president in 1877 and then served seven terms as Mexico's president. He established a strong centralized power in the country, and there was economic advancement. But the economic advancement benefited only a few. The vast rural populations were not helped; in fact, many peasants had their lands taken from them. So I'd go with answer D -- the increasing gap between rich and poor was a source of economic and political instability.
The answer is:
D. His policies increased the gap between rich and poor.