To determine the approximate distance between San Antonio and Houston using a graphic map scale, you would typically measure the distance on the map with a ruler and then compare it to the scale provided on the map.
However, based on general knowledge, the distance between San Antonio and Houston is usually around 200 miles. Given the options you've provided, the closest estimate would likely align with approximately 180 miles, which falls within the 10-mile allowance for this exercise.
So, the best response from your options is:
approximately 180 miles.