Bespoke Quizzing

Time for a classic Test your mind with this one.
Four people come to a rickety old bridge they must cross.
Only two people can cross at a time but it is dark and the four only have one torch between them.
They must cross carrying the torch whilst everyone else waits on either side of the bridge.
Person A, the oldest member of the group, takes 8 minutes to cross the bridge and anyone walking with must them go at the same speed.
At their max speed person B can cross the bridge in 5 minutes.
Person C can cross the bridge in 2 minutes unless accompanying one of the slower two.
Meanwhile person A, the fittest, can cross in 1 minute when travelling by themselves.
Accounting for all the travelling back and fore, how is it possible for the entire group to cross the bridge in 15 minutes?