Giant comet heading for Earth

The video discusses the discovery of a massive comet, Bernardinelli-Bernstein, classified as a minor planet. It is expected to make a rare visit near Earth in 2031, passing just outside Saturn's orbit. The comet has an icy core approximately 100 kilometers in diameter, making it unusually large. Its orbit takes an estimated 5.5 million years to complete, originating from the Oort Cloud, a distant spherical cloud of icy objects. The comet will eventually round the sun and return to its origin.

What is the estimated size of the comet's icy core in kilometers?

From where does the comet originate according to the text?