On April $1{?}^{st},$ Porter buys Silvester's car for $$10,000$ and they agree that Porter will pay Silvester the full amount by July $1^{st}.$ Porter begins making payments to Silvester, but on June $1^{st},$ Porter still owes Silvester $$5,000.$ On June $1^{st},$ Porter sells Anne his motorcycle for $$5,000.$ Porter and Anne agree that Anne will not pay Porter $$5,000,$ but Anne will instead pay Silvester the $$5,000$ Porter still owes him. Silvester agrees to receive the $$5,000$ from Anne. In this scenario, who is the obligor, who is the assignee and who is the assignor?

Anne is the obligor, Porter is the assignor and Silvester is the assignee.

Porter is the obligor, Anne is the assignee and Silvester is the assignor.

Porter is the obligor, Anne is the assignor and Silvester is the assignee.

Silvester is the obligor, Anne is the assignor and Porter is the assignee.