If the shear stress in a R.C.C. beam is

equal or less than $5 kg/c{m}^2$, no shear reinforcmenet is provided

greater than $4 kg/c{m}^2$, but less than $20 kg/c{m}^2$, shear reinforcement is provided

greater than $20 kg/c{m}^2$, the size of the section is changed

all the above