How can these requirements be met?

Universal Containers is implementing a new lead status process and wants to be able to do the following:

– Track leads through five different status values

– Run reports showing the duration a lead spends in each status

– Run full Lifetime reports of a lead from creation to conversion

– Prevent leads from skipping a lead status

How can these requirements be met?
A . Use lead history reporting to track changes in the lead status field, and use custom reporting fields to calculate status duration. Use validation rules to prevent status skipping
B. Use custom date fields and workflow rules for each status, and use custom formula fields for calculating duration of a status. Use validation rules to prevent status skipping
C. Use an Apex Trigger to populate custom date fields for each status, and use custom formula fields for calculating duration of each status
D. Use field history tracking on the lead status field to track the duration of each status. Use validation rules to prevent status skipping