To convert from kilometers per hour (km/h) to miles per hour (mph), you can use the conversion factor that 1 mile is approximately 1.6 kilometers.
To convert 80 km/h to mph:
\[ \text{Speed in mph} = \frac{\text{Speed in km/h}}{1.60934} \]
Using this factor:
\[ 80 , \text{km/h} \approx \frac{80}{1.60934} \approx 49.71 , \text{mph} \]
Rounding to the nearest whole number, this is about 50 miles per hour.
So the correct response is 50 miles per hour.