we know that
the scale factor produce a contraction when its value must be less than zero
Let
SF---------------> scale factor
SF< 0------------> produce a contraction
A.) 5/2 --------> 2.5 SF>0 not produce a contraction
B.) 1.2 --------> 1.2 SF>0 not produce a contraction
C.) 2.3 --------> 2.3 SF>0 not produce a contraction
D.) 3/4--------> 0.75 SF< 0 produce a contraction
the answer is 3/4