Find the last product [D] in reaction sequence

The major product of the following reaction is:

Consider the reactions:

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Identify $\mathrm{A},\mathrm{ }\mathrm{X},\mathrm{ }\mathrm{Y}$ and $\mathrm{Z}$.

cannot be prepared by:

Mention the reagents used for the following conversions:

(m) ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3\stackrel{\mathrm{A}}{\to }{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{CHO}$

(n) ${\mathrm{CH}}_3\mathrm{CHO}\stackrel{\mathrm{B}}{\to }{\mathrm{CH}}_3{\mathrm{COOC}}_2{\mathrm{H}}_5$

(o) ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{CHO}\stackrel{\mathrm{C}}{\to }{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COCH}\left(\mathrm{OH}\right){\mathrm{C}}_6{\mathrm{H}}_5$

(p) ${\mathrm{CH}}_3{\mathrm{COCH}}_3\stackrel{\mathrm{D}}{\to }{\left({\mathrm{CH}}_3\right)}_2\mathrm{C}\left(\mathrm{OH}\right){\mathrm{CH}}_2{\mathrm{COCH}}_3$

(q) ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}\stackrel{\mathrm{E}}{\to }{\mathrm{CH}}_3\mathrm{CH}\left(\mathrm{Br}\right)\mathrm{COOH}$

(r) ${\mathrm{CH}}_3{\mathrm{COCH}}_3\stackrel{\mathrm{F}}{\to }{\mathrm{CH}}_3{\mathrm{COCH}}_2\mathrm{Br}$