Usage of 言えばいいわけです in this sentence from IAIJ


I was trying to translate this sentence:

> 私は積極的に喋らないタイプなんですが、日本では私が喋らなくても、「アンディ、こう思ってるでしょう」って言ってくれるので、
> **私はただ「うん」と言えばいいわけですよね** 。

My translation is the following:

> I'm that type that do not actively talk but, in Japan, even without saying
> anything, since I get asked ”Andy, do you think it is like this?", **it is
> natural that I should say just "Yes"**

My translation for the part in bold though doesn't sound really good and
probably I'm missing something. Why is it using the 「ばいい」construct there?




In this case the ただ………と言えばいい means "it's enough for me to just say", "I only
need to say"

