To determine the approximate distance between San Antonio and Houston using a graphic map scale, a ruler would typically be used to measure the distance on the map and then convert that measurement to real miles using the scale provided on the map.
Based on general knowledge, the approximate distance between San Antonio and Houston is about 200 miles. This means if you were to consider the choices provided and round to the nearest option, the best answer would be:
approximately 180 miles.
If you have access to a specific map and scale, you could provide a more exact answer based on your measurements, but from the options given, this is the closest choice.