Answer:
Option 3 - y=-2
Explanation:
Given : Function

To find : What is the asymptote of the graph of function ?
Solution :
A function of the form
always has a horizontal asymptote at
.
On comparing with function

Here, a=1, b=4 and c=-2
The equation of the horizontal asymptote is y=-2.
Therefore, option 3 is correct.