Answer:
You did not include options however, the following is the most likely order:
1. Peninsulares
These were Spanish people who were born in Spain but lived in New Spain. They were at the top of the social ladder because they were pure Spaniards born in Spain.
2. Creoles.
The Creoles were what you might call Spanish Americans because they were children of Spanish people but were born in the Americas. They came second on the social ladder.
3. Mestizos
Mestizos were third on the social ladder because they were a mixture of both Spanish and Native Indian heritage.
4. Native Indians.
The Native Indians were at the lowest class and deliberately kept there because Spain wanted to remind them - not so subtly - that they had been conquered and were therefore not to be seen in the same vein as the Spanish.