A programmer has written the tollowing function for implementing the merge

sort algorithm, but is not sure if the function is correct.

What is true about this merge$\_$sort function?

Select one:

a$.$ It is a recursive function that will never terminate.

b$.$ The call to merge is not necessary.

c$.$ There is a mistake in the parameters passed to the recursive calls to

merge$\_$sort.

d$.$ The merge$\_$sort function works perfectly as written.