We can break the inheritance from the client task assignment from the specific group level, which is inheritance from the My ORg or top group level.
>> Select the group and edit the task and select the option: “BreakInheritance and assign the policy and setting below this point”
Select the task and click on NEXT = and select the option DISABLE and click next and save the task.
>> Then send the wake up call to all the clients under the Group B with full properties to get this updated information.
This helps to avoid the sub group B to install VSE.
Note: Check the attached snapshots for the break inheritance and from system tree ( Ex:Servers ) group is disabled the task.