Excel Solver using binary. How can I use binary to solve this question on excel? What are the step and what should i put in my solver?

The following problem is adapted from in the Balakrishnan, Render, and Stair textbook.

A trauma center keeps ambulances at locations throughout the east side of a city in an attempt to minimize the response time in the event of an emergency. The times, in minutes, from the ambulance locations to the population centers are given in the following table.

	Population Centers
Ambulance Locations	East	Northeast	Southeast	Central
Site 1	12	8	9	13
Site 2	10	9	11	10
Site 3	11	12	14	11
Site 4	13	11	12	9

1. Find the optimal assignment of ambulances to population centers that will minimize the total emergency response time. Each ambulance can service only one population center, and each population center must be serviced.