I believe it's not a function because the input (x) 4 has two outputs(y), 2 and 8.
The answer would be 3.8.
So, to get 3 to 4, you would have to multiply 3 by something to get to 4. So you would divide 4 by 3 and get 1.3. So then you would divide 5 by 1.3 to solve for k, since k times 1.3 equals 5.
5 ÷ 1.3 = 3.8.
Here is your answer
A. 1,3,5,7,9,11,.....
REASON :
In an AP their is a common difference between two consecutive terms.
i.e. t2-t1=t3-t2=t4-t3=....= constant
The option A satisfies above condition.
HOPE IT IS USEFUL