Was Einstein a Space Alien?

Modern pop culture paints scientist Albert Einstein as a bushy-haired superthinker. His ideas, we’re told, were improbably far ahead of other scientists. He must have come from some other planet—maybe the same one that scientist Isaac Newton grew up on.

“Einstein was no space alien,” laughs Harvard University physicist and science historian Peter Galison. “He was a man of his time.” All of his 1905 papers unraveled problems being worked on, with mixed success, by other scientists. “If Einstein hadn’t been born, [those papers] would have been written in some form, eventually, by others,” Galison believes.

What’s remarkable about 1905 is that a single person authored all five papers, plus the original, irreverent way Einstein came to his conclusions.

Source: NASA

Which definition reflects the meaning of the word papers in this passage?

paper

noun \pā-pər \

a piece of paper
a paper container or wrapper
a formal piece of writing that is published
paper that is used to cover the walls of a room