Soldier's Arcane Attack rules

[K0lyan]

hello, i have some questions about Arcane Attack rules.

As a standard action, you can spend 1 Resolve Point to use a weapon imbued with the rune of the eldritch knight to make an attack that strikes true. This attack ignores all cover and concealment, including total concealment (though you must at least be aware of a creature’s presence to target it with this attack). If the attack is a ranged attack, the target must be within the first range increment. The attack only affects your selected target, even if it normally affects an area or multiple targets. You still must make a normal attack roll, and if your attack misses, it has no effect.

So if i am using Plasma rifle with "line" ability or Plasma cannon with "explode". What will happen:
1) ability will hit and do damage only to 1 target?
or
2) i can choose 1 target for this attack and then cause some damage with explosion near him?

How does this skill works with grenades?

Sorry for my bad english, it isn't my native language.

[Robert Gooding]

Option 1
And same applies for grenades

[Xenocrat]

This doesn’t work with an explode weapon, because they target squares not creatures. And creatures in those squares already don’t benefit from concealment.

I think a line weapon would only target and hit a single target.