The correct answer is A. 14 cm2.

The formula for calculating the area of steel required is:

$A = \frac{wL}{bd}f_y$

where:

  • $A$ is the area of steel required (in cm2)
  • $w$ is the uniformly distributed load (in kg/m)
  • $l$ is the length of the beam (in m)
  • $b$ is the effective depth of the beam (in cm)
  • $d$ is the lever arm factor (in dimensionless)
  • $f_y$ is the permissible tensile stress of steel (in kg/cm2)

In this case, we have:

  • $w = 2400 \frac{kg}{m}$
  • $l = 6 m$
  • $b = 50 cm = 0.5 m$
  • $d = 0.85$
  • $f_y = 1400 \frac{kg}{cm^2}$

Substituting these values into the formula, we get:

$A = \frac{(2400 \frac{kg}{m})(6 m)}{(0.5 m)(0.85)(1400 \frac{kg}{cm^2})} = 14 cm^2$

Therefore, the area of steel required is 14 cm2.