The correct answer is: C. There is no relation between iso-production curve and ridge curves.
An iso-product curve is a curve that shows all the combinations of inputs that produce the same level of output. A ridge curve is a curve that shows the maximum output that can be produced with a given set of inputs.
There is no direct relationship between iso-product curves and ridge curves. Iso-product curves show the combinations of inputs that produce the same level of output, while ridge curves show the maximum output that can be produced with a given set of inputs. These are two different concepts, and there is no reason why they should be related.
In fact, it is possible for an iso-product curve to intersect a ridge curve. This would happen if the combination of inputs represented by the iso-product curve was also the combination of inputs that produced the maximum output. However, this is not a necessary relationship, and it is possible for an iso-product curve to never intersect a ridge curve.
In conclusion, there is no direct relationship between iso-product curves and ridge curves. These are two different concepts, and there is no reason why they should be related.