Find the value of x such that $x \equiv -6 \pmod 5$

Question

I have this question that is asking to find the value of x such that $x \equiv -6 (mod 5)$.

I have worked out the answer but the answer is not in the choices available to pick. This is why I decided to post this question to get a second opinion to see if I am right and if the question answer has error in it. The question provide 4 choices:

1. 1
2. 14
3. 15
4. 21

I worked my steps and concluded that x = -1. But there is no -1 here. I suppose the first choice may be -1 (perhaps the school mistake). What do you guys think?

Modified to show my working:

This working is based on what appear in my lecture notes, adjust to this question.

$x \equiv -6 (mod 5)$

$x - (-6) = 5k, k \in Z$

$x + 6 = 5$, where k = 1

$x = 5 - 6 = -1$

Edit 2:

It looks like the answer is 14. In lecture notes, it is mentioned that we can set k to any integer that will get $x \in N$. Subbing in 4 to k and multiply by 5 will result in 20. Take 20 minus 6 and the answer 14 is available.

Answer 1

It's asking: which one of these is a multiple of $5$ different from $-6$? Only one of the numbers given is so.