Final answer:
The word that best fits the blank in the sentence is noncommittal. This suggests the speaker was uncertain or undecided about the spring trip to Washington.
Step-by-step explanation:
The word that best fits the blank in the sentence is noncommittal. When the speaker replied with a "we'll see," it indicates that they were not expressing enthusiasm or skepticism, but rather holding back from making a definite commitment. This suggests that the speaker was uncertain or undecided about the spring trip to Washington.
When the mother's only reply was "we'll see," it can be best described as noncommittal. This is because a noncommittal response indicates a refusal to commit oneself to a particular opinion or course of action. Given the context, where the mother does not provide a direct answer or show a clear attitude towards the spring trip to Washington, the correct option to fill in the blank is c) noncommittal.