Can't find DecisionOptions that associated to TaskCollection /IWPGW/TASKPROCESSING Service

Hello,
I wanna use My Inbox using /IWPGW/TASKPROCESSING Service
The below is returned collections from the service :

TaskDefinitionCollection", "TaskDescriptionCollection", "UIExecutionCollection", "FilterOptionCollection", "CustomAttributeDefinitionCollection", "CustomAttributeCollection", "SubstitutionRuleCollection", "SubstitutesRuleCollection", "SubstitutionProfileCollection", "CommentCollection", "AttachmentCollection", "ProcessingLogCollection", "UserInfoCollection", "SubstitutedUsersCollection", "ConsumerScenarioCollection", "ScenarioCollection", "SystemInfoCollection", "TaskObjectCollection", "SubscriptionCollection", "NotificationCollection", "TaskCollection"

And Collections Associated to the TaskCollection:

TaskDefinitionData, Description, UIExecutionLink, CustomAttributeData, Comments, Attachments, ProcessingLogs, CreatedByDetails, ProcessorDetails, PossibleAgents, PotentialOwners, TaskObjects.

I can't find DecisionOptions that associated to TaskCollection Like WFSERVICE