To calculate the work done, you can use the formula:
\[ \text{Work} = \text{Force} \times \text{Distance} \times \cos(\theta) \]
In this case, since the person is lifting the box vertically, the angle \(\theta\) is 0 degrees, and \(\cos(0) = 1\). Therefore, the formula simplifies to:
\[ \text{Work} = \text{Force} \times \text{Distance} \]
Here, the force is 50 newtons and the distance is 0.5 meters.
\[ \text{Work} = 50 , \text{N} \times 0.5 , \text{m} = 25 , \text{joules} \]
So, the correct response is 25 joules.