The correct option is C 16
Quantity of juice that Sia needs to buy = 4 L
Now, we know that 1 L = 1000 mL
So number of juice bottles needed for extracting 1 L of juice = 1000 ÷ 250
= 4
So, the number of juice bottles needed for extracting 4 L of juice = 4 × 4
= 16
Therefore, Sia should buy 16 bottles.