Answer:
B. Ubac
Explanation:
The ubac slope typically can be found on part of the mountain which had around 40 degree slope.
The low sun angle provide little sun light compared to the top of the mountain, but still enough for the plants to conduct photosynthesis. The low evaporation makes the plants on this area able to sustain enough water within their soil. The combination of the two us the reason why Ubac managed to sustain a  relatively luxuriant vegetation growth.
