Answer:
A.
Step-by-step explanation:
The double bar around any number means absolute value. Absolute value makes any number positive.
So,
9.3 = 9.3
|-2.1| = 2.1
-13.7 = -13.7
-4.2
Negatives are always the smallest:
-13.7, -4.2, |-2.1| or 2.1, 9.3
Therefore, A is the correct answer.
