While working with MS-DOS, which command is used to combine FILE1 plus FILE2 into new file named FILE3? A. COPY FILE3 FILE1+FILE2 B. COPY FILE1+FILE2 FILE3 C. COPY FILE1+FILE2+FILE3 D. COPY FILE2 FILE1+FILE3 E. None of the above

The correct answer is: B. COPY FILE1+FILE2 FILE3

The COPY command is used to copy files from one location to another. The syntax for the COPY command is:

COPY source destination

The source is the file that you want to copy, and the destination is the location where you want to copy the file. In this case, the source is FILE1+FILE2, and the destination is FILE3. This means that the COPY command will copy the contents of FILE1 and FILE2 into a new file named FILE3.

Option A is incorrect because it does not specify the destination file. Option C is incorrect because it tries to copy the contents of FILE1+FILE2+FILE3 into a new file named FILE3. This is not possible because FILE3 already exists. Option D is incorrect because it tries to copy the contents of FILE2 into a new file named FILE1+FILE3. This is not possible because FILE1+FILE3 does not exist. Option E is incorrect because it is not a valid command.