Correct Option: A

vagueness (Noun) : unclearness by virtue of being vague or not clear
perspicuity (Noun) : clarity as a consequence of being perspicuous or easily understandable
dullness (Noun) : the quality of being slow to understand; lacking interest
unfairness (Noun) : injustice by virtue of not being equitable
unwillingness (Noun) : the quality of not willing to do something