What is the most distinct difference between a spin and a spiral dive? (Ref: VFR SOP Page 178)

• A) In a spin, airspeed is constant (and low), in a spiral dive it increases rapidly
• B) In a spin altitude is rapidly gained, in a spiral dive it is lost
• C) In a spiral dive the aircraft is stalled, in a spin it is not
• D) They are both the same