The answer would be C valleys formed by a glaciers.
Using statistics.
Make a tree diagram - probability adds up to 1
<span>Scientists are looking for a way to create cheap, safe, and sustainable energy.
Nuclear fusion is the process by which two atoms rapidly collide at each other forming a new nucleus. The energy of colliding and synthesizing has intrigued scientist into believing that this could be one of best sources of renewable energy. </span>
