In order to change celcius to kelvin always add 73 to it leaving you with -195.93
Absorbance measures the ability of the substance to absorb light at a specific wavelength.
Absorbance is also equal to the product of molar absorptivity, path length and molar concentration.
The mathematical expression is given as:
(1)
where, A = absorbance
= molar absorptivity
l = path length
c = molar concentration.
The above formula is said to Beer's Law.
Absorptivity of protein x = 
Path length = 1 cm
Molar concentration = 
Put the values in formula (1)

= 
Thus, absorbance at 280 nm = 
Experimentation is the best way to obtain knowledge, because it is the only actual factual thing in the options