Concrete Technology and Design of Concrete Structures
If the depth of neutral axis for a singly reinforced rectangular section is represented by kd in working stress design, then the value of k for balanced section

is independant of both ast and acbc where d is the effective depth, ast is per-missible stress in steel in tension and ocbc is permissible stress in concrete in bending compression.
depends on both crst and acbc
depends on as, only
depends on aCbC only