Heather is engaged to either Abe, Brad, Cody, or Dean. Each of the four men plus Heather is either a Knight, who always tells the truth or a Liar, who always speaks falsely.
Their statements are as follows:

• Abe says, "Exactly one of us four men always tells the truth".
• Brad says, "Exactly one of us four men always lies".
• Cody says, "Heather's fiancé is either Abe or Brad."
• Heather says, "My fiancé and I either always tell the truth or always lie".

Who is Heather's fiancé? What are the types of the five individuals?