Hi John,
Unfortunately, the situation has not been changed in this area - it is still not possible to execute a test item or a set of test items from command line. The only real possible options are either script mentioned by you as option a) (or, maybe a little more handy https://support.smartbear.com/viewarticle/54655/ one) or to create a driver program using any regular programming language so that this driver instantiates an instance of TestComplete's COM object and command it to execute this or that test item. (Yes, this functionality is accessible via COM.)