Politician: The bill that makes using car phones while driving illegal should be adopted. My support of this bill is motivated by a concern for public safety. Using a car phone seriously distracts the driver, which in turn poses a threat to safe driving. People would be deterred from using their car phones while driving if it were illegal to do so.

The argument's main conclusion follows logically if which one of the following is assumed?

【选项】The only way to reduce the threat to public safety posed by car phones is through