What is the difference between a call feature and a sinking-fund provision? Briefly describe the three different types of call features. Can a bond

What is the difference between a call feature and a sinking-fund provision? Briefly describe the three different types of call features. Can a bond be freely callable but non-refundable?

Question: What is the difference between a call feature and a sinking-fund provision? Brieflydescribe the three different types of call features. Can a bond be freely callable but nonrefundable?...