The reason why San Antonio's location was important when it was founded in 1718 was B.It was midway between the Spanish settlements on the Rio Grande and the missions in East Texas.
San Antonio was established on an area that was midway between Spanish missions located to the east of Texas and settlements in the Rio Grande area.
This made it a great place for supplies and people to pass through on their way to both places.
Find out more on San Antonio at https://brainly.com/question/3144167.
#SPJ1