We know it's a linear function, which is like
We can find the slope "m" of the linear function doing
There the points x₂, x₁, y₂ and y₁ we can take what's more convenient for us, just be careful, if you do x₁ = 0, you must take the correspondent y₁, the value of y on the same column, therefore y₁ = 3, for example.
I'll do x₁ = 0 which implies y₁ = 3 and x₂ = 1 which implies y₂ = 7. Therefore
Therefore the slope is m = 4, then
To find out the "b" value we can use the fact that when x = 0 we have y = 3, therefore
Then b = 3, our equation is
The correct equation is the letter A.