Correct Answer - Option 1 : 2.5
According to IS 456-2000 a beam shall be deemed to be a deep beam when the ratio of effective span-to-overall depth, l/D is less than:
1) 2.0, for simply supported beam; and
2) 2.5, for a continuous beam.
Though different codes define deep beams in different clear span-to-depth ratios, as a general rule deep beams are recognized by their relatively small span-to-depth ratio.
Hence, Deep beams are designed for bending moment and checked for shear.
Reference: IS 456:2000 page 51.