What Was the Policy Advocated by Government Ministers in the 1970s

What was the policy advocated by government ministers in the 1970s and especially the 1980s termed 'bifurcation'?

A) long custodial sentences would be reserved for the violent, dangerous and those from whom the public need protection
B) prisoners would have to take a twin tracked approach
C) shorter sentences or non-custodial sentences would be increasingly used for the more run-of-the-mill offenders