Input : play over 49 37 12 match now 81
Which of the following will be step IV?

In the first step, the word that comes first in the alphabetical order comes to the first and the rest of the shift rightward. In the next step largest number occupies the next place and the rest of the shift rightward. This goes on alternately till the words get arranged in the reverse alphabetical order and number in a descending order.
As per given question,
Input : play over 49   37   12 match now 81
Step I : play 81 over 49   37   12 match now
Step II : play 81 over 49   now 37   12 match
Step III : play 81 over 49   now 37 match 12
Since the line is already arranged, there will be no step.