Explanation:

Let's evaluate the given regression lines for the point $y=-3$:

- Equation 1: $x+4y+1=0$

- Substitute $y=-3$: $x+4(-3)+1=0$

- Simplify: $x-12+1=0$

- Result: $x=11$

- Equation 2: $4x+9y+7=0$

- Substitute $y=-3$: $4x+9(-3)+7=0$

- Simplify: $4x-27+7=0$

- Result: $4x-20=0$

- Solve for $x$: $4x=20$

- Therefore, $x=5$

- The correct value of $x$ when $y=-3$ is 5.

Correct Option:

- Option 3: 5