I'm still fuzzy on what the "it" in Elder's text refers to. Donald
has confirmed that it's not as simple as "it" being "the action card" (because if it were, then all plays of that action card this turn would be modified by Elder. So it seems like "it" must be something more like "this instance of playing the action card".
If it were simply "the action card" instead, then the answer to this question would be simpler, the card you played with Elder didn't give you any "choose one" instructions. Since it's not as simple as that, assuming that the answer given above is correct, then the "it" in Elder must mean something that eliminates indirect effects of playing the card and only cares about the text on the card itself.
In other words, the answer above (which I think is correct) seems to require "it" to mean "the action card", because "the playing of the card" did give you a choice of abilities, even though "the card" itself did not*. So it's kind of like "it" on Elder has to mean "the action card, as a result of being played by Elder".
To remove any ambiguity around Ways and stuff like that, the same question always could have been asked with simply playing Elder, choosing Throne Room, choosing Pawn.
*A bit more on this... I don't think there's a clear-cut set of rules defining what object actually "does" a thing in Dominion. Imagine if instead of "when it gives you a choice[...]" Elder said "when it makes you draw cards". Then you play it on a Festival that has your +1 card token on it. [The Festival] didn't make you draw cards, but [playing the Festival] did. That seems clear to me, and if Elder, instead of "it" simply used "[playing the card]", then I would find that wording strongly suggesting that Festival with a +1 card token should trigger whatever its ability is.