b-r-r — to sift, to sort out, to make clear
ב.ר.ר (barar) starts as sifting grain and ends as clarity — the same root gives Hebrew "obvious", "it turned out that", and the word for an alternative.
The word family
Every word below is built on ב.ר.ר. Same three letters, different vowels and prefixes.
Everyday Israeli confirmation: בָּרוּר! — "obviously", "of course".
הִתְבָּרֵר שֶׁ... is how a news report says "it emerged that".
אֵין בְּרֵרָה (ein brerah), "there is no choice", is one of the most-used phrases in Israel.
Roots this gets confused with
These look close in transliteration and are not close in Hebrew.
What I tell students about this root
This is the root that shows what Hebrew does with a physical image. You start with a farmer separating grain from chaff, and every abstract word follows from that one motion: sorted becomes clear, clarifying becomes investigating, and the leftover pile of things you could have picked becomes the word for an option.