With a stage micrometer scale, one division of an eyepiece graticule was found to equal $0.005\ \text{mm}$. A spongy mesophyll cell measured $3.5$ divisions on the eyepiece graticule. What is the estimated diameter of the cell?
- A$0.18\ \mu\text{m}$
- B$1.8\ \mu\text{m}$
- C$18.0\ \mu\text{m}$
- D$180\ \mu\text{m}$