Final answer:
The division of 20 by 3, limited to four significant figures, results in 6.667, making the closest multiple-choice answer A. 6.67.
Step-by-step explanation:
To calculate 20÷3, you can use long division or a calculator. When using a calculator, it's important to remember that calculators will provide as many decimal places as their program allows, even though not all of those digits may be significant based on the precision of the input numbers. However, since 20 and 3 are exact numbers, we can consider all the decimals provided in this case.
Using division, 20÷3 equals approximately 6.66666667. When limiting this result to four significant figures, it becomes 6.667. Therefore, the answer closest to the calculated value is option A. 6.67.