The opponent does not claim that any of the proponent's terms are ambiguous.

The proponent’s argument is not self-contradictory, nor does the opponent claim it is. The opponent addresses the proponent’s argument by presenting an additional consideration about irradiation that the proponent does not mention, and proposing an alternative method to irradiation.

This might be tempting because the opponent certainly discusses undesirable consequences of the irradiation process. But he does not mention any undesirable consequences of the chemical dip method, which is the only other remedy proposed in the stimulus. So it's not true that the opponent claims undesirable consequences will result from adopting "either one" of the two remedies.

The opponent does not say anything about safety with respect to producers. Both the proponent and the opponent focus on risks with regard to consumers.

This is correct. The proponent claims that irradiation has the advantage of killing Salmonella. The opponent points out that irradiation also brings a significant disadvantage — killing the bacteria that warn of botulism, but not killing botulism bacteria themselves — and suggests an alternative method, a chemical dip that kills both Salmonella and botulism.