The following statement(s) on the CPF is/are correct EXCEPT:
I. Self-employed persons with net trade income exceeding $6,000 are required to contribute to their Medisave accounts only.
II. To enhance employability for older workers, the compulsory employers' contribution for workers aged above 50 will be lower.
III. There is no limit to the amount of contribution, both compulsory and voluntarily, that can be paid to a member's CPF account.
A: I only.
B: II only.
C: I and II only.
D: II and III only.