The disadvantages of "Compile and Go" loading scheme is (are):

• A. a portion of memory is wasted because the core occupied by the assembler is unavailable to the object program.
• B. it is necessary to retranslate the user's program deck every time it is run.
• C. it is very difficult to handle multiple segments, especially if the source programs are in different languages, and to produce orderly modular programs.
• D. all of the above