Arlene owes Betty $100. Betty owes Chris $250. Betty pays $150 to Chris and assigns (in writing) Arlene's debt to Chris in satisfaction of the remainder of what she owes. Chris gives notice to Arlene that she should pay him the $100 and not Betty. Arlene ignores the notice from Chris and pays Betty. Whom should Chris sue to recover the $100? Chris may sue only Arlene because she ignored the proper notice. O Chris cannot sue either Arlene or Betty in this case. O Chris may sue only Betty because she has the money. O Chris must sue both Arlene and Betty. O Chris can successfully sue either Arlene or Betty