Final answer:
The advantage of all countries adopting the same accounting standards is comparability and potentially lower preparation costs, enhancing transparency and easing economic decision-making.
Step-by-step explanation:
One of the primary advantages of all countries adopting and following the same accounting standards is comparability. When companies from different countries use a uniform set of accounting standards, it enables investors, authorities, and other stakeholders to compare financial statements with ease.
This comparability leads to greater transparency and helps in making informed economic decisions, which is crucial in today's globalized world.
Moreover, consistent standards across nations can potentially lead to lower preparation costs for multinational corporations as they would not need to prepare multiple sets of financial statements according to different national standards. Therefore, the best answer to the question would be option B) Comparability and lower preparation costs.