Why should band steering algorithms allow stations to connect to the 2.4 GHz band after some number of ignored Probe Requests?

Why should band steering algorithms allow stations to connect to the 2.4 GHz band after some number of ignored Probe Requests?
A . Because the FCC requires it.
B . Because some clients are persistent clients that will not move on to the 5 GHz band.
C . Because the 802.11 standard requires it.
D . Because the AP will experience a buffer overflow if they do not eventually respond with a Probe Response.

Answer: B