Question

jim brown was a type of running back never seen before in the game of football. he was quick and fast like many halfbacks, yet he was also massive and terribly strong. his muscular body was hard as stone. and when he ran, he often ran right over anyone who tried to tackle him. this passage is probably part of— a poem about an amazing athlete a biography or biographical essay an autobiography an encyclopedia entry about football

Explanation:

The passage describes Jim Brown, a unique running back in football, highlighting his physical traits and playing style. A biography or biographical essay focuses on a person's life and achievements, which matches this content. A poem would have more figurative/literary language, an autobiography is from the person's own perspective (this isn't), and an encyclopedia entry on football would cover the sport generally, not an individual player.

Answer:

a biography or biographical essay