A student measures the length of a spring. She then hangs different weights on the spring. For each weight, she records the spring’s length. Her results are shown in the table. What is the extension of the spring when a weight of $3.0\,\text{N}$ is attached to it?
- A$4\,\text{mm}$
- B$5\,\text{mm}$
- C$12\,\text{mm}$
- D$13\,\text{mm}$