B is the answer to your question
Pio de Jesus<span> was the last governor of Mexican California.</span>
I would say that B is the most accurate. This is because:
Pull factor is something that makes someone want to <em>arrive </em>in a new country.
Push factor is something that makes them want to <em>leave </em>an old country.
B states that fighting in a homeland, something that a normal civilian wouldn't want to take part in, would make someone want to <em>leave</em> their country.
So, the answer is B!