Since she has "no more than $40 to spend" we know that the the symbol must be "less than or equal to"
. Now we can eliminate the first and second choices because they are "greater than or equal to".
Next, we can figure out how to model this situation. There is a flat $5 fee and each song is $2. We can model this with 2s+5 ($2 per son plus $5).
The answer is

Hope this helps!