Does having a conversation with a passenger increase the risk of a vehicle crash in the same way that speaking on a cell phone while driving increases crash risk?

Select one:

a$.$ There is no increased crash risk when a driver speaks with the front$-$seat passenger, but conversations with back$-$seat passengers have been shown to increase crash risk as much as using a hand$-$held cell phone.

b$.$ There is no increased risk of a vehicle crash when the driver speaks with a passenger; some studies suggest that there are fewer crashes when there is a passenger in the vehicle with the driver.

c$.$ A normal conversation might increase crash risk by a small amount; a heated argument is more likely to increase crash risk and teen drivers with passengers also tend to face an increased crash risk.

d$.$ The increased risk of a vehicle crash when speaking with a passenger is similar to the increased crash risk of speaking on a cell phone while driving.