Read the passage. excerpt from "Marie Curie and the Discovery of Radioactivity" by Mara Rockliff

To the Austrian mine owners who had sent the pitchblende ore, it was just dirt. After all, they had already taken out the valuable part—the metallic element called uranium—and dumped what was left over in a nearby pine forest. If a pair of eccentric French scientists wanted them to scoop up the worthless stuff and ship it, the mine owners were happy to oblige.

PLZ HELP

It could be inferred that the word pitchblende in the paragraph means "a black mineral deposit."

Which context clue best helps confirm this meaning of the word pitchblende?

"they had already taken out the valuable part—the metallic element"

"ore, it was just dirt"

"and dumped what was left over in a nearby pine forest"

"the mine owners were happy to oblige"