(DSE)數學延伸部分計選修科嗎?

Not necessary.

The key is either M1/M2 must be one of the recognized optional subject for the JUPAS programs you selected.

For example, M2 will be accepted for sciences programs, such as physics. But it will not count towards arts programs like history.

Please note - meeting the minimum requirement does not mean you have a chance for a JUPAS program. Most programs actually require 4433 in the reality, especially sciences programs.