Out of the ones that you mention, the correct answer should be
<span> Operating system</span>
There's another question I found like this which 2 people answered with either C2 or B3. (B3 was rated with 5 stars but I don't know if that was the user them-self)
Answer:
The answer to this question is given in the explanation section.
Explanation:
Let look at each option:
Add color to the table
If we add color to the table it will be some what visible
Draw lines on the table
I think there is no need to draw lines as table has already lines.
Add borders to the table:
This is the correct answer, as adding border will separate each value and will make them clearly visible
Insert lines into the table.
I think this option is same as draw lines on the table.