The muscles that extend the forearm are located the muscles that extend the forearm are located medially anteriorly laterally posteriorly

There are  around 640 to 850 muscles in human body and they can be categorized in three main groups: skeletal, visceral, and cardiac. 
The muscles that extend the forearm are located posteriorly. These are the muscles located on the back.

Centration is the correct answer

What do you mean about innate behavior i don’t get it