please be specific with answer its one question due soon pls ( timed )

Tunningley Services is establishing a new business to serve customers in the Ohio, Kentucky, and Indiana region around the Cincinnati, Ohio area. The company has identified 12 key market areas and wants to establish regional offices at some of the key market areas to meet the goal of being able to travel to all key markets within 40 minutes. The accompanying data file provides travel times in minutes between each pair of cities. a. Develop and solve an optimization model to find the minimum number of locations required to meet their goal. b. Suppose they change the goal to 90 minutes. What would be the best solution? Click the icon to view the table travel times between each pair of cities. b. To travel to all key markets within 90 minutes, a minimum of regional offices are required. (Type a whole number.)