The maximum efficiency of a screw jack is

The maximum efficiency of a screw jack is A. 1−sinφ1+sinφ1−sin⁡φ1+sin⁡φ B. 1+sinφ1−sinφ1+sin⁡φ1−sin⁡φ C. 1−tanφ1+tanφ1−tan⁡φ1+tan⁡φ D. 1+tanφ1−tanφ1+tan⁡φ1−tan⁡φ Answer: Option A