How to update option set values in Cancelled state through plugin

Hi All,

In service activity entity cancelled state i added 2 option set values A, B. I created one option set on the form Test type, values are A,B.

when i am clicking cancelled button on ribbon bar window is displayed completed , cancelled like.. i am selecting cancelled state option value  A,  same value will update on form Test type option value A.

i tried plugin SetState and SetStateDynamicEntity messages. it's not working

Please Help me any one.