A proposed rule requires the installation of guardrails on all traffic bridges in the state of Willericka. However, an engineer argued that because traffic accidents on bridges account for only 2 percent of all traffic accidents in Willericka, guardrails would do little to reduce the number of traffic injuries.
Which of the following, if true, would most seriously weaken the engineer’s argument?
【选项】
The installation of warning signs on bridges costs significantly less than the installation of guardrails.
选项是否正确？