Is it a or d?
b and c don’t make sense to me

D. An observation is based on evidence, an inference is not.

Explanation:

When you infer something, you're basically guessing at it, while an observation is something that you can see and prove.

transformative rocks are the stones that emerge from the transformation of existing rock composes in a procedure called changeability, implies changing of structures. transformative rocks are shaped from alternate shakes that are changing a result of warmth or weight connected. one of this model is the earth developments that making rocks profoundly cover or crushed which will make the stones warmed and put under awesome weight. they are not softening but rather the minerals they are containing are changed synthetically that will shape transformative rocks. now and again different rocks are shaped when the others are near some liquid magma and getting warmed.