'I Will Give You a Piece of Bubblegum, Since You

'I will give you a piece of bubblegum, since you helped me fix my car yesterday'. This is not a binding promise because…? Please select all that apply.

A) Past consideration is no consideration.
B) It is not a good bargain.
C) The piece of bubblegum is not economically valuable.
D) The piece of bubblegum is a gift.