When Does the "Post-Effective" Period Begin and End

When does the "post-effective" period begin and end?

A) It begins when the registration statement becomes effective, and runs until the issuer either sells all of the offered securities or withdraws them from sale.
B) It begins when the registration statement becomes effective, and runs until the issuer sells all of the offered securities.
C) It begins when the registration statement becomes effective, and runs until the issuer withdraws the offered securities from sale.
D) It begins forty-five days after the registration statement is filed, and runs until the issuer either sells all of the offered securities or withdraws them from sale.
E) It begins sixty days after the registration statement is filed, and runs until the issuer sells all of the offered securities.