At first look we can exclude option D because the number of elements in the array is 3, the result of multiplying the two array dimensions 1 x 3.
We can run the code
public class Main {
public static void main(String[] args) {
int num[][] = new int[1][3];
for (int i=0; i<num.length; i++) {
for (int j=0; j<num[i].length; j++) {
num[i][j] = 10;
System.out.println("num[" + i + "][" + j + "]= " + num[i][j]);
}
}
}
}
the output is
num[0][0]= 10
num[0][1]= 10
num[0][2]= 10