Answer:
The answer is actually A) "X and Y are both within the solar system."
Explanation: For answer B. the solar system is equal to 287.46 billion km which is less than 1 light year not to mention 7.2 of them! So not this answer.
I was looking at the other persons answer and was about to enter it on my exam but then I realised "30.2 astronomical units is not equal to even one light year" 30.2 AU is 0.00047754 light years. So a light year is a lot bigger than an astronomical unit if you recall. So it couldn't be C.
For D., going back to my explanation about light years, the entire solar system is not even equal to 1 light year and Earth isn't bigger than the solar system. So that means that there is no way that Y and Z are present on Earth, being that they are over seven light years apart.
So that leaves you with A) "X and Y are both within the solar system. " because their distances do not exceed that of the solar system, and the other answers were incorrect.
Hope this helps :))