The electrical conductivity of a sample of semiconductor is found to increase when electromagnetic radiation of wavelength just shorter than $$2480\,\text{nm}$$ is incident normally on its surface. The band gap of the semiconductor is

A

$$1.96\,\text{eV}$$

B

$$1.12\,\text{eV}$$

C

$$0.50\,\text{eV}$$

D

$$0.29\,\text{eV}$$