According to the information provided in this class, how do the risks of speaking on a hand$-$held cell phone while driving compare with the risks of speaking on a hands$-$free headset while driving?

Select one:

$$ a$.$ Speaking on a hand$-$held cell phone while driving increases crash risk by about $10\%,$ while using a hands$-$free device carries zero risk

b$.$ Speaking on a handsfree device is riskier than using a hand$-$held cell phone

$$ c$.$ Speaking on a hand$-$held cell phone while driving is just as risky as using a hand's$-$free Sevice

$$ d$.$ Although not quite as hazardous as a hand$-$held cell phone, using a hands$-$free device still increases the chances of a crash