To reflect a point across the x-axis, you change the sign of its y-coordinate while keeping the x-coordinate the same.

From the image, point $K$ is located at $(1, 4)$.

The reflection of $K$ across the x-axis will result in $K'$, which has the coordinates $(1, -4)$.

Thus, the correct answer is $(1, -4)$.

Would you like more details or have any questions? Here are 5 related questions for further exploration:

1. What are the new coordinates for points $C$, $J$, and $M$ after reflection across the x-axis?
2. How would the reflection change if it were across the y-axis instead of the x-axis?
3. Can you describe the rule for reflecting a point across the origin?
4. What transformations, other than reflections, could change the position of the shape on the coordinate plane?
5. What is the general formula for reflecting a point across the line $y = x$?

Tip: When reflecting across the x-axis, only the y-coordinate changes its sign while the x-coordinate remains constant.