The correct answer is C. Iso-product curves do not intersect each other.
An iso-product curve is a curve that shows all the combinations of inputs that produce the same output. It is downward sloping to the right because as you add more of one input, you need less of the other input to produce the same output. It is convex to the origin because it is more efficient to produce more output by using more of both inputs rather than using more of one input and less of the other.
If two iso-product curves intersected, it would mean that there were two different combinations of inputs that could produce the same output. This is not possible, because the production function is a mathematical relationship that shows how much output can be produced with different combinations of inputs. If two iso-product curves intersected, it would mean that the production function was not a single-valued function, which is not possible.