Class 12th

All structure can produce -CHO functional group which gives +ve test of Tollen's reagent except structure (II), because if forms ketonic group after tautomerisation

$X\underset{H_{2}S{O}_4}{\overset{Conc}{\to }}$ Brown fumes + Brown ring test with FeSO₄/H₂SO₄

$x\underset{HCl}{\overset{H_{2}S}{\to }}Y\left(ppt\right)\underset{HN{O}_3}{\overset{Conc}{\to }}dissolved\underset{N{H}_{4}OH}{\overset{}{\to }}$ Deep blue colour solution

In cation analysis of Cu⁺ ions, precipitate formed is CuS on treating with H₂S and HCl which dissolved in HNO₃ and produced blue colour complex solution ${\left[Cu{\left(N{H}_3\right)}_4\right]}^{++}$ in NH₄OH. Brown fumes and brown ring performance given by nitrate sample. Hence salt is Cu (NO₃)₂.

Candidates seeking admission to the BTech programme can enrol for admission with Class 12 marks. Candidates must complete Class 12 to enrol for the BTech course. The college offers only one UG course, i.e., BTech. National Fire Service College admissions are based on entrance exam.

2^nd sentence introduces the subject and gives further information about it in 4^th sentence; the use of pronoun 'it' in 1^st  and 3^rd  sentence gives further account of the subject.

As the first sentence talks about how companies are planning to open new stores in the future. While other sentences mainly focus on the sale of diapers in supermarket and their prices.

All 1, 2 and 3 specifically talk about mental health and well-being. Sentence D deviates from the topic as it is talking about Mental maths which is totally different in context. Hence, 4 is the odd sentence here.