Unifiedshoe

The term "rules lawyer" isn't applicable here. This is a question of basic geometry vs the intention of the rules as written. It's a fault of the rules document that this is not more clearly spelled out. 

I disagree that lines are possible in perfect alignment - in perfect alignment it is impossible to draw a line between A and C that doesn't touch B first and therefore get blocked

 

Even if that "touching" is only a tangent, that is the exact same amount of "touching" that the line will do to the attacker and target models.

This isn't open for debate, it's a fact. If three circles of the same size are in perfect alignment, you will be able to draw parallel lines that touch all three models bases on both sides. Just go draw it in paint or something to see what I'm talking about. That same line that touches the first circles base also touches the second and third circles, meaning that circles 1 and 3 "see" each other. In order for the middle circle to block 1 from 3 and vice versa, it would have to interrupt the line. It clearly doesn't, since the line continues to touch all three circles.

Option 1 is correct.

If models a-b-c are the same size, then it's not possible in any way for model B to block LOS to either. If they are not perfectly lined up, one base edge will be blocked and the other will be visible. If they are perfectly aligned, BOTH base edges of A, B, and C will be visible to all three models.