Babies who are able to explore novel environments, are minimally disturbed by brief separations from their parents, and are quickly comforted by their parents when they return have a:

Haley is 2 months old. Which of the following motor milestones is she likely to have most recently attained?

a. chest up c. standing with help b. sitting with support d. grasping object

The cerebral cortex is:

A) gray B) about 1.5 to 5 millimeters thick C) divided into two hemispheres D) in the forebrain E) all of the above