Final answer:
The statement about vagueness of words is true because words with borderline cases can be interpreted in various ways. The word 'suggestion' is closest in meaning to 'hypothesis' because it represents a proposal that is not yet confirmed.
Step-by-step explanation:
The statement 'A word is vague to the extent that it has 'borderline cases' in which there is no precise way to determine whether the word applies' is indeed true. Vagueness in language arises when words or phrases have indeterminate boundaries of application, leading to ambiguity and the possibility of interpreting the term in various ways. For example, consider the word 'tall'. What qualifies as 'tall' can vary greatly and has many borderline cases where it's hard to say definitively whether someone or something is 'tall' or not.
Regarding the options provided for the word closest in meaning to 'hypothesis', the most fitting answer would be suggestion (d). A hypothesis indeed refers to a proposed explanation or idea that is yet to be proven.