Depending on the data all answers can be used to make it easier to read. Without more info I would go with Borders (D) since they are the best way to group the data when printed, especially if the print is in color.
Alignment would be the correct answer only if the data goes out of cell boundaries. Font Color usually makes it harder to read because of bad contrast and finally changing the Font Style has a minimal effect since the default one is already pretty readable.
Answer:
Double spaced means more space in between lines and there is an option in Google Docs or Word to make it double spaced. One inch margin means that there is one inch between the edge of the paper and where the words start.
Answer:
Occurs when a specific language construct was expected, but something else was provided.
