Get return value from each iteation in the blockingcollection

I have a blockingcollection.

private BlockingCollection<Tuple<ChannelResource, string>> bc;

Now I want to process each item in it.

private bool ProcessEachChannel(Tuple<ChannelResource, string> workItem)
  {
        ChannelResource cr = workItem.Item1;
        string sipuri = workItem.Item2;
        VoiceResource vr = workItem.Item1.VoiceResource; 
        bool success=false;
        try
        {

I don't know how to get the return bool value in the ActionBlock code.

 internal void SimultaneousCall()
        {
            var workItemBlock = new ActionBlock<Tuple<ChannelResource, string>>(
               workItem =>
               {
                   ProcessEachChannel(workItem);
               });

            foreach (var workItem in bc.GetConsumingEnumerable())
            {
                workItemBlock.Post(workItem);
            }

            workItemBlock.Complete();
        }

You see that there are two lines code, I am not sure whether I get the bool value from

ProcessEachChannel(workItem); // I mean bool b= ProcessEachChannel(workItem);

Or from

workItemBlock.Post(workItem); // I mean bool b = workItemBlock.Post(workItem);

Eventually I want to get the statistics of how many success or fail. Sorry fr the stupid question.