Final answer:
In the context of the narrative, the word 'excitedly' is the correct choice to describe how Ratu responded to the boy's news and ran towards the creek.
Step-by-step explanation:
The correct word to fill in the blank space within the paragraph about 'A Naughty Boy' is d. excitedly. This word fits the context of the paragraph as Ratu runs towards the creek with a feeling of eager enthusiasm, hoping to see the baby bear that the boy mentioned. The boy's mischievous act of deceiving Ratu and stealing a watermelon would typically instigate such an excited response.