which of the following correctly relates the mesher of diamiter d and ratios r of a circle

The mesher of a circle ????

that's a new one, and of course the AI went right along with it, lol
it was dumb enough to even call the radius of a circle " ratio r "

So I give up; what is the question?

To correctly relate the mesher (circumference) of a circle with diameter d and the ratio r, you would use the formula:

Circumference = π * d

If you want to relate the circumference to the radius instead of the diameter, you can use the formula:

Circumference = 2 * π * r

Please note that the value π (pi) is a mathematical constant approximately equal to 3.14159.

The mesher of a circle with diameter d and ratio r is equal to d/r.