We can also think in this way:
The total number of inversions in any array = ((n)(n-1))/2
At every step: n/2 inversions are getting corrected.
So the total number of steps required will be = ((n)(n-1))/2) / (n/2) = n-1 steps
Example:
let the number of elements in the array be n = 8.
The total numbers of inversion possible = (8*7)/2 = 28
The number of inversions corrected 1 step = 4
The total number of steps needed to correct 28 inversions = 28/4 = 7, approximately equal to n
So the option C