Answer:
A. 105 and 128
Explanation:
We know that,
'Relatively prime numbers are the numbers having 1 as the only common factor'.
According to the options,
A. 105 and 128: The only common divisor of these numbers is 1.
B. 130 and 273: They have 13 as a common factor other than 1.
C. 205 and 350: They have 5 as a common factor other than 1.
D. 273 and 333: They have 3 as a common factor other than 1.
Thus, the only pair of numbers which are relatively prime are 105 and 128.