Rearrange the following sentences in correct order to make a logical passage.
1. The plan is approved after consent from all partners.
2. First, a preliminary outline is drafted.
3. Then modifications are made after consultations.
4. Finally, implementation starts according to schedule.
A2-3-1-4
B1-3-2-4
C3-2-1-4
D2-1-3-4
