Which salt is used during the bead test in the qualitative analysis of inorganic substances?

The salt used for performing the 'bead' test in qualitative inorganic analysis is

Assign $A, B, C, D$ from the given type of reaction.
$Na_2CO_3 + KNO_3 \longrightarrow$ No reaction

Given below are two statements:
Statement $I$: Colourless cupric metaborate is reduced to cuprous metaborate in a luminous flame.
Statement $II$: Cuprous metaborate is obtained by heating boric anhydride and copper sulphate in a non-luminous flame.
In the light of the above statements,choose the most appropriate answer from the options given below.

The microcosmic salt is

$A$ chemistry student trying to detect the metallic ion in a salt,makes a paste on a clean platinum wire loop of the salt with concentrated $HCl$. When he takes a small amount of this paste and keeps it in a non-luminous Bunsen flame,the colour of the flame changes to grassy green. He should,therefore,conclude that the metal is