Final answer:
The foal took tentative steps towards the open palm with the apple.
Step-by-step explanation:
The word that best fits the blank in the sentence is tentative. The context of the sentence suggests that the foal was taking small and cautious steps towards the open palm with the apple, frequently checking back at its mother. This indicates a sense of hesitation or uncertainty, which aligns with the meaning of the word 'tentative'.
Learn more about The meaning of the word 'tentative' in a sentence