A. It depends on the length and nature of the quote. If it is a short quote that simply expands on or backs up a point you wish to make, you probably don't need to ask permission. But give credit as to the person quoted and the source of the quote. If the quote is more substantial—such as one of the major premises in that author's book—t hen you will want to ask permission.
It is important to maintain a balance concerning quotes. Don't ask for permission when not needed and don't fail to ask when you should.