She is incorrect cause if we take the number 20 and take 25% of it it equals 5 so now 20 is only 15. They if we take 75% away from 20 is equals 15 so then we only have 5 from 20 left. Therefore she’s incorrect because 75% leaves 5/20 and 25% leaves 15/20. Hope that makes sense.
<h2>
Hello!</h2>
The answer is: 
<h2>
Why?</h2>
Domain and range of trigonometric functions are already calculated, so let's discard one by one in order to find the correct answer.
The range is where the function can exist in the vertical axis when we assign values to the variable.
First:
: Incorrect, it does include 0.4 since the cosine range goes from -1 to 1 (-1 ≤ y ≤ 1)
Second:
: Incorrect, it also does include 0.4 since the cotangent range goes from is all the real numbers.
Third:
: Correct, the cosecant function is all the real numbers without the numbers included between -1 and 1 (y≤-1 or y≥1).
Fourth:
: Incorrect, the sine function range is equal to the cosine function range (-1 ≤ y ≤ 1).
I attached a pic of the csc function graphic where you can verify the answer!
Have a nice day!