Why did spainish leaders want to push spainish control into north america in themid 1500's

The correct answer is C. Spain wanted to keep European rivals far away from valuable towns and mines in Mexico.
The further the Spanish were into North America, the harder it would be for the Europeans to gain access to their mines. However, you should post the answer choices next time, or you won't get lucky enough to find somebody taking world history currently. :)

Hope this helps!