Question

reread the sentences from the passage. consider what happened thousands of years ago when people detected a large animal nearby. if they didn’t think they had a good chance of outrunning the predator, they might have stayed very still so it wouldn’t notice them. according to psychologist mark seery, the body’s arteries contracting made sense in that case, because less blood flow makes it easier for muscles to freeze. this reaction likely saved early humans’ lives. a large animal nearby psychologist mark seery a good chance of outrunning the predator the body’s arteries contracting? complete the sentence. likely saved early humans’ lives.

Explanation:

We need to find what "likely saved early humans’ lives" according to the passage. The relevant sentence is "This reaction likely saved early humans’ lives", and "this reaction" refers to "the body’s arteries contracting" as explained earlier (arteries contracting to help muscles freeze, which made sense when facing a predator). The other options: "A large animal nearby" is the situation, "Psychologist Mark Seery" is the one explaining, and "A good chance of outrunning the predator" is a condition for a different action, not the thing that saved lives.

Answer:

The body’s arteries contracting