ISTQB-Foundation -chapter4-question9

        2. A wine storage system uses a control device that measures the wine cell temperature T (measured in °C, rounded to the nearest degree) and alarms the user if it deviates from the optimal value of 12, according to the following rules: 

• if T = 12, the system says, “optimal temperature”
• if T < 12, the system says, “temperature is too low!”
• if T > 12, the system says, “temperature is too high!”

You want to use the 3-point boundary value analysis (BVA) to verify the behavior of the control device. A test input is a temperature in °C provided by the device.

What is the MINIMAL set of test inputs that achieves 100% of the desired coverage?