Why does form 1099-B say stocks were SOLD if I INHERITED them only?

My mom passed in 2014 and my sisters and I inherited/split the stocks when the estate was closed in 2016. 
Filling in the blanks, I was asked if Federal was withheld and Turbo stated that as an "unusual" event.
Entering all the info was actually satisfying as I understood UNTIL I didn't!
It has raised my total gross income by THOUSANDS and is trying to give me a VERY LARGE Federal refund.

Although that would be great, it doesn't seem to make any sense.
I did NOT sell these stocks
Because it says QUANTITY SOLD, who sold them and more importantly, where or to whom was it sold?

Thank you in advance!!!