A) That depends of our timetable but we can if we are in high school. If some teachers are absent, you can start at 2.
B) Yes in both systems, everyone has to go to school except people who are suffering from diseases or are handicapped person. In fact they go in specials schools for handicapped person.
In short, the statement is true for both systems
C) In France, you can stop the school when you have 16.
D) Not in France. When you come in High school and you do your 11th year,
you have the option of choosing the sector S, ES or L, technologic, etc...
Some of these sector don't propose math and science because it is not very helpful for these sector.
Hope this helps !
Photon