Exam 300-425 topic 1 question 163 discussion

The issue, which is described in the question, is that the roaming happens when it should not. And we need to answer why the device roams. After googling, I believe the answer here is D. If the disassociation imminent feature is disabled, another feature which could cause the client to roam is "Optimized Roaming". https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-0/hdx_final/b_hdx_dg_final/high_density_experience_features_added_in_release_8_0.html#topic_E673759007A04204ACB90A203D582F80

when AP is sending a BSS Transition Management query to the client, that is related t o 802.11V and Optimized Roaming and in this case you can enable or add Disassociation Imminent , references : https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/201015-802-11v-Basic-Service-Set-BSS-on-AireO.html#anc10

A nad D goes together , as i understood , the issue is not roaming as expected , answer B Disassociation Imminent - The Disassociation Imminent option sets a flag in 11v request telling the client that it needs to roam, or it will be disassociated after a certain amount of time.