The 2nd row of ur keyboard its called home row !
Answer:
B. Replace the Bluetooth headset with a new pair.
Explanation:
Since all other mobile devices, after receiving the "corporate-wide" OS update, aren't having issues with pairing with Bluetooth headsets, we can safely conclude that the OS update isn't the issue.
To find out if the Bluetooth headset is not the culprit, we can try to pair the mobile device with a different headset. If it pairs correctly, then we can conclude that the old Bluetooth headset might have a fault, or it might need to be disconnected/forget from the device and paired gain.