The correct answer is: $4\text{ fl oz}$
Explanation
In US volume measures, 1 cup = 8 US fluid ounces, so half a cup is half of that. (Note: “ounces” can mean weight (oz) or volume (fl oz); here we mean US fluid ounces.)
Steps:
- First step: $$1\text{ cup}=8\text{ fl oz}$$
- Second step: $$\tfrac{1}{2}\text{ cup}=\tfrac{8\text{ fl oz}}{2}$$
- Final step: $$\tfrac{8\text{ fl oz}}{2}=4\text{ fl oz}$$
If you want the metric equivalent: $$4\text{ fl oz}\times29.5735\text{ mL/fl oz}=118.294\text{ mL}$$ (commonly rounded to $120\text{ mL}$).