Correct Answer:
B. Nine
The phrase 'A stitch in time saves nine' is a common English idiom. It means that it is better to deal with a problem immediately, because if you wait, it will become worse and take more effort to solve. The number 'nine' is the traditional and correct completion of this proverb, implying that a small effort now can prevent a much larger effort later. Options A ('Five'), C ('Seven'), and D ('Eleven') are incorrect as they do not complete the established idiom and would render the proverb meaningless.