If we have a non terminating (repeating or non repeating) decimal representation of the fraction, it can't be displayed accurately.
A. x is 106 or 107. For (say) 106, a denominator of 2 would display correctly (53), but a denominator of 3 would not (35.33333333333). Insufficient.
B. x is any value. y is 4 or 5. For any fraction (with a whole number as the numerator), a denominator of 4 would produce terminating decimal representation of (.0, .25, .5 or .75) and a denominator of 5 would produce a terminating decimal representation of (.0, .2, .4, .6, or .8), none of which is non terminating. Besides, the number of digits for the quotient for dividends upto 1000 doesn't exceed 3. Thus sufficient.
Who says elephants can't dance?