Answer: OPTION B
Step-by-step explanation:
Let be "x" the acceptable lengths for the rod.
You know that the ideal length of the metal rod is 30.5 centimeters and the measured length may vary from the ideal length by at most 0.015 centimeters.
Therefore, knowing this, you can say that the acceptable lengths must be:
[tex]30.5cm-0.015cm\leq x\\\\30.485\leq x[/tex]
[tex]x \leq 30.5cm+0.015cm\\\\x\leq 30.515[/tex]
Therefore, the range of acceptable lengths for the rod is the following:
[tex]30.485\leq x\leq 30.515[/tex]
This range matches with the one shown in the option B.