Answer:
A. The ability to signal and change lanes properly
C. Good knowledge of the area
Explanation:
It is required to find 'the first line of defense against a deadly collision'.
Even if the person has the ability to pay attention, it will not be fruitful during a collision as merely being attentive does not stop accidents.
So, option B is not correct.
So, having the ability to signal and change the lanes is very necessary in order to prevent a deadly collision as it provides the power to the person driving.
Moreover, having a good knowledge of the area is also very useful as the person can change lanes according to the area and also choose the roads less likely to result in accidents.
Hence, options A and C are correct.