Which test is used to detect the presence of halogens in an organic compound?

Lassaigne's test is not used for the detection of the element . . . . . . in the organic compound.

The Beilstein test is used for the detection of:

Given below are two statements:
Statement $I$ : Sulphanilic acid gives esterification test for carboxyl group.
Statement $II$ : Sulphanilic acid gives red colour in Lassaigne's test for extra element detection.
In the light of the above statements,choose the most appropriate answer from the options given below :

Lassaigne's test is not used for the detection of which element?

In the qualitative test for the identification of the presence of phosphorus,the compound is heated with an oxidizing agent. It is further treated with nitric acid and ammonium molybdate,respectively. The yellow-coloured precipitate obtained is: