Refer to the exhibit. MSTP is implemented in the topology shown in the exhibit, and all the switches are in the same region. The network administrator does not want to use the Internal Spanning Tree…

Refer to the exhibit. MSTP is implemented in the topology shown in the exhibit, and all the switches are in the same region. The network administrator does not want to use the Internal Spanning Tree (IST) or instance 0 for production traffic. How many non-IST spanning tree instances does this network need in order to have effective load sharing on the uplinks from the access switches?