Though I don't come across graphs like these too often, I guess the answer should be A because...
From the graph, it is clear that **Leaf 1** has more mass than **Leaf 2** after 5 hours. This means there is a lower rate of transpiration in Leaf 1, which can definitely be explained by a thicker cuticle (since the thicker the cuticle, less is the water lost). Hence **choice A** is **correct**.
Now, look at choice C. Like you said, in leaves where stomata are protected by hairs, there will be lower rate of transpiration. Then, obviously **Leaf 2** should have a higher mass than **Leaf 1** , right? But this is not the case (as per the graph). Hence, **choice C** is **incorrect**.