On a number line, the numbers increase as one moves from left to right and decrease on moving from right to left.
We have the next numbers of weights:
0.9 ounce
0.85 ounce
1.0 ounce
0.6 ounce
Now, we need to order from least to greatest. Therefore:
0.6 ounce
0.85 ounce
0.9 ounce
1.0 ounce
The number line increases from left to right.
So, it should start at 0.6 ounces and should end at 1.0 ounces.
Hence, the correct answer is option A.