Stirrups are used in a concrete beam:_______
a. to increase the beam's compressive strength.
b. to provide tensile strength in the beam since concrtete's tensile strength is negligible.
c. to increase the tensile strength of the beam beyond that provided by concrete.
d. to provide shear strength in the beam because concrete's shear strength is negligible.
e. to increase the shear strength of the beam beyond that provided by the concrete.