The correct option is B y=ax+bx+cx2
At x = 1, y = 4; and x = 2, y = 8
4 = a + b and 8 = 2a + b
⇒a=4,b=0
So, y=ax+b⇒y=4x
The other values do not satisfy this last equation. So option (a) is not fit.
Similarly, we can find that option (c) is also not fit, but option (b) is absolutely fit.