Option 1 states that Kelvin temperature (T) and Celsius temperature (tc) are two independent temperature scales. This means that they do not have any relationship between them. However, this is not correct. Kelvin and Celsius scales are interrelated.

Option 2 states that T = tc, suggesting that Kelvin temperature is equal to Celsius temperature. This is also incorrect because Kelvin and Celsius scales have different zero points and thus, they cannot be equal.

Option 3 states that T = tc - 273 • 15. This equation is incorrect as it multiplies 273 with 15, which is not the correct conversion factor between Kelvin and Celsius scales.

Option 4 states that T = tc +273-15. This is the correct relationship between Kelvin and Celsius temperatures. To convert Celsius temperature to Kelvin, we need to add 273. And as the Celsius scale has a 0 point 15 degrees lower than the Kelvin scale, we subtract 15 from the Celsius temperature.

In conclusion, option 4 is the correct relation between Kelvin and Celsius temperature.