A developer created three Rollup Summary fields: Total_timesheets_c,

A developer created three Rollup Summary fields: Total_timesheets_c,

Total_Approved_timesheet_c and Total_project_Timesheet_c in the custom object, project _c

Now, the developer is tasked with created a new field to show the ratio between and approved
A . No test methods will be executed during deployment.
B . A test class that validates the formula field is needed for deployment.
C . Using a formula field reduces maintenance overhead.
D . A formula field will calculate the value retroactively for existing records.

Answer: C,D