Question

Someone

Answer 1

I have an answer that is not among the choices. Sorry.

Answer 2

have you tried drawing any of these transformations out?

Answer 3

i think its c

Answer 4

its d

Answer 5

i think

Answer 6

it always amazes why students dont try this.
Let's test solution a:

Answer 7

Now it is obvious that, that particular solution is 90 degrees i.e. perpendicular to the original solution

Answer 8

agree with @vocaloid