Consider the following Util class, which contains two methods. The completed sum$1$D method returns the sum of all the elements of the $1-$dimensional array a$.$ The incomplete sum$2$D method is intended to return the sum of all the elements of the $2-$dimensional array m$.$

A $16-$line code segment reads as follows. Line $1$: public class Util. Line $2$: open brace. Line $3$: forward slash, asterisk, asterisk, Returns the sum of the elements of the $1-$dimensional array a$,$ asterisk, forward slash. Line $4$: public static int sum $1$D$,$ open parenthesis, int, open square bracket, close square bracket, a$,$ close parenthesis. Line $5$: open brace, forward slash, asterisk, implementation not shown, asterisk, forward slash, close brace. Line $6$: blank. Line $7$: forward slash, asterisk, asterisk, Returns the sum of the elements of the $2-$dimensional array m$,$ asterisk, forward slash. Line $8$: public static int sum $2$D$,$ open parenthesis, int, open square bracket, close square bracket, open square bracket, close square bracket, m$,$ close parenthesis. Line $9$: open brace. Line $10$: int sum equals $0,$ semicolon. Line $11$: blank. Line $12$: forward slash, asterisk, missing code, asterisk, forward slash. Line $13$: blank. Line $14$: return sum, semicolon. Line $15$: close brace. Line $16$: close brace.

Assume that sum$1$D works correctly. Which of the following can replace $/*$ missing code $*/$ so that the sum$2$D method works correctly?

Three code segments. The first segment has $4$ lines of code that read as follows. Line $1$: for, open parenthesis, int k equals $0,$ semicolon, k less than m$,$ dot, length, semicolon, k$,$ plus, plus, close parenthesis. Line $2$: open brace. Line $3$: sum, plus, equals sum $1$D$,$ open parenthesis, m$,$ open square bracket, k$,$ close square bracket, close parenthesis, semicolon. Line $4$: close brace.

The second segment has $4$ lines of code that read as follows. Line $1$: for, open parenthesis, int, open square bracket, close square bracket, row, colon, m$,$ close parenthesis. Line $2$: open brace. Line $3$: sum $,$ plus, equals sum $1$D$,$ open parenthesis, row, close parenthesis, semicolon. Line $4$: close brace.

The third segment has $7$ lines of code that read as follows. Line $1$: for, open parenthesis, int, open square bracket, close square bracket, row, colon, m$,$ close parenthesis. Line $2$: open brace. Line $3$: for, open parenthesis, int v$,$ colon, row, close parenthesis. Line $4$: open brace. Line $5$: sum, plus, equals, v$,$ semicolon. Line $6$: close brace. Line $7$: close brace.

Responses

I only

I only

II only

II only

I and II only

I and II only

II and III only

II and III only

I, II$,$ and III