Hello, Basia,
These questions, like most LSAT questions, are much easier if you can break down and rephrase the sentences to be more clear.
![Smile :)](./images/smilies/smile1.gif)
In this case, let's take the first half of the first sentence.
"None of the students taking literature are taking physics..."
This can be rephrased into a conditional reasoning if-then statement.
"IF a student is taking literature, THEN that student is not taking physics."
The second part:
"...but several of the students taking physics are taking art."
This isn't conditional reasoning, but it stands for this statement:
"NOT NONE of the students are taking both art and physics."
Not none means some, but it can be easier to interpret things in terms of All/Not All, None/Not None, if you have trouble with some and several and those. Last part:
"None of the students taking rhetoric are taking physics."
If/then again:
"IF a student is taking rhetoric, THEN that student is not taking physics."
Summed up:
IF a student is taking literature, THEN that student is not taking physics.
IF a student is taking rhetoric, THEN that student is not taking physics.
NOT NONE of the students are taking both art and physics.
So this shows us that answer choice A must be true. It must be true that some students are taking both art and physics, and it also must be true that a student taking literature is not taking physics. So there must be at least some students that are taking art but
not literature.
Hope that helps,
Lucas Moreau