Which statement correctly explains why $(x+3)$ and $(x-3)$ cannot be canceled termwise in a rational expression?

They represent the same polynomial evaluated at different points, so cancelation depends on substituting a test value to check equality before canceling

They can be canceled termwise because the variable terms match and constants differ only by sign, so cancelation is allowed when numerators and denominators are linear

They are opposites and always simplify to -1, so cancellation is unnecessary but valid in all algebraic manipulations

They are not identical factors, so term‑by‑term cancellation is not valid in a rational expression