What constitutes an unescorted transport? Detailed question

It is still not clear to me when referring to submarines firing on unescorted transporters. What constitutes an unescorted transport?  This is a question that affects all three games (Pacific, Europe and Global).  I posted in Europe because this is where everybody is now.  I apologies upfront if this topic has been beat to death already in the Pacific thread; I couldn’t find it and can no longer use the search feature.

In the rule book of AAP40 on page 30, under Submarines, under Does Not Block Enemy Movement, it stats that “There is and exception to this rule, however.  A submarine can attack any transporter that move into or though its sea zone unaccompanied by surface warships, in either combat or non-combat movement.”  Nowhere does it explain the definition of unaccompanied.  It is not addressed in the Errata except in the Q&A section where it stats;
Q. Submarines can attack transports that move through their sea zone “unaccompanied by surface warships”. Under exactly what conditions do surface warships prevent sub attacks on moving transports?
A. In order to prevent sub attacks, a transport or group of transports must make its entire move accompanied by a specific surface warship or group of surface warships. Each transport or group of transports that is not escorted will be fired upon once by each sub in the sea zone.

In example 1; Battleship in zone 10 (A) moves to zone 9 (B).  Both battleship and transport move form zone 9 to zone 14 © were enemy submarine waits.  Then both battleship and transport move form zone 14 to zone 25 (D) ignoring the sub.

In example 2; Transport in zone 10 (A) moves to zone 9 (B).  Both battleship and transport move form zone 9 to zone 14 © were enemy submarine waits.  Then both battleship and transport move form zone 14 to zone 25 (D) ignoring the sub.

Here are the three possibilities:

a. Both these example constitute an escort since both battleship and transport are together in zone 14 at the same time where the enemy Sub waits, resulting in the transport not taking fire from the submarine?  From the sub perceptive they are traveling the same rout in and out of its zone ©.

b. Only example 1 counts as an escorted move since the transporters entire move was escorted by the battleship (as stated in the Q&A), it did not state they had to start together.  Then the sub would only be able to fire on the transport in example 2 because that transport was not escorted its entire move therefore in example 1 the transporter should be safe.

c. Neither counts as escorted since the battleship and transporter in each example did not travel the entire rout exactly together thereby each is considered a separate moves and the sub will fire at the unescorted transport.

I think the first one of these (a) is the simplest way to keep track of during a game; however the second one (b) does technically fit the explanation in the F&Q section.  But, is that reading too much into it, and we are left with the entire rout being together as listed in ©.  I would just like to know the official answer, the way it was designed by Larry and crew to be played.

Thanks Krieghund