Answer :
Instead "tan x°" in your question must be:"...what is the value of sin x° ?"
In that case: sin x° = tan x° · cos x° = 3 / y · y / z = 3 / z
Answer: A ) sin x° = 3 / z
In that case: sin x° = tan x° · cos x° = 3 / y · y / z = 3 / z
Answer: A ) sin x° = 3 / z