Answer: c. It is important to know the value of a dollar
Explanation: The expression above, in quotes "In the world today, we all know the value of a dollar." could be explained as a statement which is aimed at expressing or intensifying how important the dollar currency is. In truth, not everyone in the world knows the value of the dollar currency. However, with the popularity of the dollar and it's global acceptance in world trade, knowing and understanding the value of a dollar is paramount and essential.