Which reagent is suitable for the following transformation?

$A$ primary alcohol was reacted with pyridinium chlorochromate $(PCC)$,which resulted in a product $P$. The product $P$ on treatment with ammoniacal silver nitrate solution produces:

The correct order of rate of reaction toward nucleophilic addition reaction for the following compounds is:
$(a)$ $p-NO_2-C_6H_4-CHO$
$(b)$ $C_6H_5-CHO$
$(c)$ $p-OMe-C_6H_4-CHO$
$(d)$ $CH_3-CO-CH_2CH_3$
$(e)$ $C_6H_5-CO-C_6H_5$

Which of the following reagents would carry out the following transformation? ($D = $ $^2H$)

Which of the following compounds gives the iodoform test?

Which one among the following compounds will most readily be dehydrated under acidic condition?