Evolution of man was possible because our ape-like ancestors 

Evolution of man was possible because our ape-like ancestors showed bipedal movement on open land. Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. The greatest advantage of bipedal movement is forearms becoming free for carrying out the order of brain. It also raises the head; this allows a greater field of vision with improved detection of distant dangers or resources, access to deeper water for wading animals and allows the animals to reach higher food sources with their mouths. So, the correct answer is option A.