Consider a class MatrixStuff that has a private instance variable: private int $[][]$ mat;

Refer to method alter below that occurs in the MatrixStuff class. $($The lines are numbered for reference.$)$

Line $1$: $/**$ Oparam mat the matrix initialized with integers

Line $2$: $*$ Oparam c the column to be removed

Line $3$: $*$ Postcondition:

Line $4$: $*-$ Column $c$ has been removed.

Line $5$: $*-$ The last column is filled with zeros.

Line $6$: $*/$

Line $7$: public void alter$($int $[][]$ mat, int c$)$

Line $8$: $\{$

Line $9$: for $($int $i=0$;$1$ mat.length; $1++)$

Line $10$: $,$ for $($int $j=c$;$j$ mat $0.$length; $j++)$

Line $11$: $,$mat$[1][j]=$mat$[1][j+1]$;

Line $12$: $//$code to insert zeros in rightmost column

Line $13$: $,..$

Line $14$: $\}$

The intent of the method alter is to remove column $c.$ Thus, if the input matrix mat is

$\backslash$table$[[2,6,8,9],[1,5,4,3],[0,7,3,2]]$

the method call alter $($mat$,1)$ should change mat to

$\backslash$table$[[2,8,9,0],[1,4,3,0],[0,3,2,0]]$

The method does not work as intended. Which of the following changes will correct the problem?

I Change line $10$ to

for $($int $j=c$;$j$ mat $[0].$length $-1$; $j++)$ and make no other changes.

II Change lines $10$ and $11$ to

for $($int $j++$mat$[1][j-1]=$mat$[1][j]j=j>cj--$mat$[1][j-1]=$mat$[i][j]j=c+1$;$j.$ length; $j++$