Eidolon attack enhancement evolutions

[Barstro]

Two Eidolon evolutions contain the phrase "Pick one attack" (Reach, Poison)

Assuming it has two sets of limbs with claws (four attacks), does "Pick one attack" mean for Reach;
1) one claw attack
2) two class claw attacks (one set of limbs)
3) all claw attacks

How about "Select one natural attack form? (Increased Damage)

Poison can be used only once per round. If it applies to all tail attacks, does the player get to choose which attack poisons? Does he have to say it's a poison attack before rolling?

[Halna LeGavilk]

Two Eidolon evolutions contain the phrase "Pick one attack" (Reach, Poison)

Assuming it has two sets of limbs with claws (four attacks), does "Pick one attack" mean for Reach;
1) one claw attack
2) two class attacks (one set of limbs)
3) all claw attacks

How about "Select one natural attack form? (Increased Damage)

Poison can be used only once per round. If it applies to all tail attacks, does the player get to choose which attack poisons? Does he have to say it's a poison attack before rolling?

I don't know Eidolon, but if it says one attack, it means one attack, as in "One Claw Attack" or "One Wing Attack" If it specified one natural attack form, then it would apply to all of a given natural attack form. Personally, I would keep as is.

It can be used by one attack, he gets to choose which attack poisons, and yes, he must declare.

[Yorrin]

I don't know Eidolon, but if it says one attack, it means one attack, as in "One Claw Attack" or "One Wing Attack" If it specified one natural attack form, then it would apply to all of a given natural attack form. Personally, I would keep as is.

It can be used by one attack, he gets to choose which attack poisons, and yes, he must declare.

This is correct.

As to your "select one natural attack form" that means pick claw(s) or bite(s) or tail(s) etc. Where all attacks of that form benefit.