3 species of Begonia on the slope limestone hill

This limestone hill is really amazing! Between 200 feet to 400 feet, got 3 species of Begonia growing on the mossy limestone wall.

At 200 feet, the ground is very dark & humid. Here, I found this Begonia - species A.

Begonia species B found on the drier wall at 300 feet high. Here is not so humid & got more sunlight. Looks very similar to Begonia speluncae from Bau area.

Begonia species C is growing on the cliff at 400 feet high. Here is windy & got even more sunlight.