Beilstein test is used for the estimation of which one of the following elements?

The Beilstein test is a flame-test that detects the presence of halogens—especially chlorine—in an organic compound.

Procedure: A clean copper wire is dipped in the organic sample and then introduced into a non-luminous Bunsen flame. If the compound contains chlorine (or another halogen), volatile $$CuX_2$$ (where $$X$$ is a halogen) forms on the hot copper surface. This vapour colors the flame green due to the emission spectrum of excited copper halide species.

No green coloration appears with sulphur, nitrogen, carbon or hydrogen alone. Hence the test is specific for halogens, with chlorine giving the most intense and reliable green flame.

Therefore, Beilstein test is used for detecting chlorine.

Option B which is: Cl