A map has a scale of 1:1,000,000. If the distance between two points on the map is 8 cm, what is the actual distance in kilometers?

Assuming the length of line MN as depicted in the image is $8 \text{ cm}$.

The scale of the map is $1:1,000,000$. This means that $1 \text{ cm}$ on the map represents $1,000,000 \text{ cm}$ in actual distance.

We know the following conversion factors:
$1 \text{ m} = 100 \text{ cm}$
$1 \text{ km} = 1000 \text{ m}$
Therefore, $1 \text{ km} = 1000 \times 100 \text{ cm} = 100,000 \text{ cm}$.

To convert $8,000,000 \text{ cm}$ to kilometers, divide by $100,000 \text{ cm/km}$:

The calculated actual distance is $80 \text{ km}$.
A. 80000
B. 8000
C. 80
D. 8

The calculated value matches option C.

The final answer is $\boxed{\text{C. 80}}$