Option 1: Compression is borne entirely by concrete
This is true for normally loaded singly reinforced beams but during reversal of loads due to earthquakes, wind loads etc the steel may take up compression
Option 2: Steel possesses initial stresses when embedded in concrete.
This is false. In RCC steel does not possesses any initial stress when embedded in concrete.
In prestress beam, steel possesses initial stress when embedded in concrete.
Option 3: Plane sections transverse to the centre line of the beam before bending remains plane after bending. This is an assumption that used in flexural analysis