To locate the service connection string in IoT Hub, which left-hand menu entry should you select?

The correct choice is to select the entry for Shared access policies in the left-hand menu of the IoT Hub. This is where you can find the service connection string, which is critical for authentication and connecting applications and services to the IoT Hub.

In IoT Hub, shared access policies define rules for what operations can be performed by a service or device connected to the Hub. Each policy can be associated with specific permissions, such as sending messages to the hub, receiving messages from the hub, or managing devices. By selecting Shared access policies, you can view, create, or configure these policies, and each policy provides a connection string that includes the required credentials to authenticate with IoT Hub.

Locating the service connection string in this area is essential for developing and deploying applications that require secure and authorized access to your IoT devices and services interacting with the IoT Hub. This access string can then be used in your applications to connect seamlessly while adhering to the set permissions defined by the shared access policy.