To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) delete j - This option is incorrect because the pointer j was assigned a new value from argv[1] using the assignment operator. Thus, delete j would only delete the memory allocated for the new value of j, not the previously allocated memory.
Option B) free j - This option is incorrect because the free function is used to deallocate memory allocated using the malloc function in C. In this code snippet, the memory was allocated using the new operator in C++, so free should not be used.
Option C) it is not supposed to be deleted - This option is incorrect. Memory allocated dynamically using the new operator should be deallocated using the delete operator to prevent memory leaks.
Option D) delete [] j - This option is correct. The new operator with [] was used to allocate an array of characters, so the delete[] operator should be used to deallocate the memory. This will ensure that the entire array is deallocated properly.
The correct answer is Option D. This option is correct because it uses the appropriate delete[] operator to deallocate the dynamically allocated array of characters.