Because genetics is now progressing so rapidly.
The subordinate clause starts with a subordinating conjunction and contains the entire dependent clause. Because is a subordinate conjunction and makes the clause dependent because you need to know what's next. Hopefully answer choice D has all the right pieces. The main clause is "it is revolutionizing medical research". This clause is a complete idea by itself and is not a subordinate clause.
I think All because we have to check for coherence just in case there are INcoherence words that don't make sense and the grammar might be written with mistakes. So also Proofreading and reviewing the sentence structures! ALL OF ABOVE
