Determine all real values of 's' such that the set of all linear combinations of ( {u} = (s, 3) ) and ( {v} = (2, 7) ) is all of ( ℝ² ). Justify your answer.
a) ( s ) can be any real number.
b) ( s ) must be equal to 2.
c) ( s ) must be equal to 3.
d) ( s ) must be equal to 5.