You need a slight stop there to collect your thoughts, especially when the next word is achromatopsia. That makes D wrong.
If you use B, " A medical condition that limits her vision" is not a sentence. So B shouldn't be the answer. Fragments are used by very good writers usually in fiction, and this statement is not part of something that is fictional.
A semicolon separates two equal clauses. You can think of it as meaning "and" or even "but" sometimes. You have the same problem with C as you do with B. So C is not correct.
That leaves us with A. That should be your answer.You need a pause of some kind and that pause is proved by the comma. The sentence is not a run on sentence just one in need of a pause in the middle.
Nepal is so beautiful and cultured i love it
No, violence is never the answer to any solution to the world, just look at our troops fighting over in the Middle East? We've been at this war for years and all it has done was created more conflict, violence can also result to death. Such as gun violence!
But considering the fact that not most people take the time to sit and talk about it, which I believe the best way to solve a problem is... just to sit down and take the time to talk about it, not to get physical or pick up a gun and end a life.
