Sandy purchased a used car from Rhonda. While Sandy was operating the car, the car unexpectedly began to shake violently. When Sandy took the car to her mechanic, the mechanic told her the frame had been damaged in an accident. Sandy sued Rhonda in a federal district court claiming fraud. Sandy's complaint alleged that while Sandy and Rhonda were negotiating the price of the car, Rhonda told Sandy that she had never had an accident in the car. Based upon that representation, Sandy purchased the car from Rhonda. After Rhonda answered the complaint and during discovery, it was determined that Rhonda had purchased the car from Ben, and Ben had been in an accident with the car. Ben never told Rhonda that the car had been involved in an accident when Rhonda purchased it from Ben. It was also determined that Rhonda did not get into an accident with the car while Rhonda owned the car. Sandy wants to dismiss her complaint against Rhonda. What are the requirements for a voluntary dismissal of an action under the Federal Rules of Civil Procedure based upon the foregoing facts