Based on the characteristics of our sun which include its temperature and luminosity, the best letter to place it on the HR Diagram, is Letter B.
The sun has a temperature of 5,530 degrees Celsius which means that it will be between the temperatures 6,000°C and 3,000°C and only letter B is in that temperature range.
The sun's luminosity is 1 solar luminosity units and letter B is also in that range.
In conclusion, letter B is correct.
Find out more on solar luminosity at https://brainly.com/question/25981690.