You have a Skype for Business Server 2015 infrastructure that is configured for audio/video conferencing and Enterprise

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You have a Skype for Business Server 2015 infrastructure that is configured for audio/video conferencing and Enterprise Voice.
Users report that they cannot connect to audio conferences from a branch office. The branch office is secured and has limited connectivity to other offices.
The users can connect to audio conferences from other offices.
You need to configure the port range used by Skype for Business clients for audio conferencing.
Which Skype for Business Management shell cmdlet should you run?

A. Set-CsConferencingConfiguration
B. Set-CsNetworkConfiguration
C. Set-CsExternalAccessPolicy
D. Set-CsMediaConfiguration