To determine the approximate distance between San Antonio and Houston within 10 miles, you would need to use the map scale. In this case, the map scale shows 80 miles and 80 kilometers. Since the distance between San Antonio and Houston on the map is not specified, you can use the ruler or a measuring tool to measure the distance in miles and compare it to the map scale.
If the measured distance between San Antonio and Houston is less than 80 miles on the map, then the approximate distance would be less than 80 miles.
If the measured distance between San Antonio and Houston is between 80 and 160 miles on the map, then the approximate distance would be between 80 miles and 160 miles.
If the measured distance between San Antonio and Houston is between 160 and 240 miles on the map, then the approximate distance would be between 160 miles and 240 miles.
If the measured distance between San Antonio and Houston is between 240 and 320 miles on the map, then the approximate distance would be between 240 miles and 320 miles.
Based on the given information, none of the provided options match the approximate distance between San Antonio and Houston within 10 miles.