A. is most fitting for the answer
The Grand Canyon is an example of physical weathering.
Another example is a landscape called karst formed by chemical weathering
It’s definitely either a or d, my guess would be d
The change that was made in the second sentence is that it created a compound sentence. The correct answer is option B. The compound subject now has two independent clauses: "The holidays are just around the corner" and "I need to go shopping". The independent clauses are connected with the coordinating conjunction "so".
