What does Designate an initial state in every concurrent region of a concurrent composite state mean?

• A. If there are no transitions to a concurrent composite state s boundary, then concurrent regions do not need to have initial states
• B. A transition to the composite state s boundary could be added later, though, so initial states for each region should always be specified
• C. It is legal to transition directly to more than one sub-state of a concurrent composite state without going through a fork
• D. All of the mentioned