What describes the palmer grasp in infants?

The palmer grasp is characterized by the use of the fingers and palm to secure an object, primarily involving the fingers curling around an item. This reflexive behavior is most prominent in infants and is typically observed when an object is placed in their palm.

In the context of option A, it accurately captures the essence of the palmer grasp, emphasizing the involvement of the fingers and palm while noting that the thumb may not be actively engaged in this reflexive action.

The other options misrepresent aspects of the palmer grasp. For instance, the full use of all fingers and thumbs as indicated in option B suggests a more complex manipulation that comes later in development. The notion that the palmer grasp only occurs at birth, as stated in option C, is also limited, since this grasp can be observed for several months thereafter as the infant's motor skills evolve. Lastly, option D's description of using the whole hand without finger movement does not accurately reflect the coordinated use of the fingers that characterizes the palmer grasp. Hence, the correct choice effectively describes the specific nature of this reflex in infants.