DS2 Opportunity Fire

Another question about opportunity fire:

A-----------------------------------I------B-----I-----------------C

						      X

A tank unit of 5 tanks are moving from A to C.
They get into optimum range of opponent unit X at location B.
Line of sight is blocked to the left and right of the 'I's.
X wants to take opportunity fire on the tank unit A at location B.

Now, I have rarely (read never) seen anyone move the entire tank unit as
a
whole (that is every miniature simultaneously). Usually I see the
elements
moved one at a time.

When does player X have to declare opportunity fire?
  When the first element reaches B?
  At any time an element is at B?
  Before the last element is at B?.
  Other?

Where are the rest of the elements of unit B placed?
  In a line at B?
  In a row at B?
  Same formation as started at A?
  Same formation that ended at B?
  Any formation that maintains unit integrity at B?
  Only the element a B, all other where they are? (seems very cheesy)

Often it makes a difference on cover or range.

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Brian Bell
bkb@beol.net
http://members.xoom.com/rlyehable/ds2/	     
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