The diagram illustrates an insect as it appears under the microscope’s low power lens. The circle’s actual diameter is $0.3\,\text{cm}$. What is the insect’s approximate length in millimetres?
- A$0.1\,\text{mm}$
- B$1.0\,\text{mm}$
- C$2.0\,\text{mm}$
- D$3.0\,\text{mm}$