The correct answer to this open question is the following.
Although there are no options attached we can say the following.
The "caste-like strata" of the French colony of Saint-Domingue was the following.
We are talking about the Island of Haiti in the times of the French presence and colony.
When the French ruled Haiti, the social class was the following.
The classes were primarily divided by race, by the color of the skin.
At the very top of the pyramid were the Europeans, the white people, Then, the mulattoes, half white half black. Then, the free blacks. ANd at the bottom of the class pyramid, the black slaves.
And, of course, these blacks in Haiti were African descendants that were very poor, had poor nutrition, had diseases, no medical attention, and worked for long hours under the sun.