The correct answer is: $0.7\text{ cm}$
Explanation
To convert millimeters to centimeters, use the fact that $1\text{ cm} = 10\text{ mm}$, so each millimeter is $0.1\text{ cm}$.
Steps:
- $1\text{ cm} = 10\text{ mm}$
- $1\text{ mm} = \frac{1}{10}\text{ cm} = 0.1\text{ cm}$
- $7\text{ mm} = 7 \times 0.1\text{ cm} = 0.7\text{ cm}$
Therefore, $7\text{ mm} = 0.7\text{ cm}$.