Answer:
B. Shining brightly in the sky, the Sun is a huge source of light
Step-by-step explanation:
A subordinate clause is a phrase which cannot make sense or be complete on its own, for example, "shining brightly in the sky" is not a complete sentence.
however it is added to a sentence that is already complete "The sun is a huge source of light." which makes the first phrase a subordinate clause.