B is corrent. Both assignment and factoring are methods of generating cash from AR. An assignment occurs when the owner of the receivables (assignor) obtains a loan from the lender (assignee) by pledging the AR as collateral. Factoring is a sale of receivables. "Factors" are intermediaries that buy receivables from companies (for a fee) and then collect payments directly from the customers.
A is incorrect because factoring is also a method to generate cash from accounts receivable.
C is incorrect because an assignment is also a method to generate cash from accounts receivable.
D is incorrect because assignments and factoring are methods to generate cash from accounts receivable.
