North Korea, Saudi Arabia.
Answer:
.d) Gibson and Walk demonstrated that most babies displayed depth perception by they time they could crawl.
Explanation:
The study by Gibson and Walk titled The Visual Cliff concluded that most children can discriminate depth as soon as they can crawl and display depth perception. Even though their mums called across from the other side of the cliff, of the 36 infants used in the study, only 3 walked across the cliff to meet their mum.
