In the given reaction sequence, the percentage of oxygen in compound $(Q)$ is . . . . . . $\%$. (Nearest integer)

Which of the following statements regarding chemical properties of acetophenone are wrong?
$(1)$ It is reduced to methyl phenyl carbinol by sodium and ethanol
$(2)$ It is oxidised to benzoic acid with acidified $KMnO_4$
$(3)$ It does not undergo electrophilic substitution like nitration at meta position
$(4)$ It does not undergo iodoform reaction with iodine and alkali

The end product $(C)$ in the following sequence of reactions is:
$HC \equiv CH$ $\xrightarrow[20\% \ H_2SO_4]{1\% \ HgSO_4} A$ $\xrightarrow[H_2O]{CH_3MgX} B$ $\xrightarrow{[O]} (C)$

Consider the above reaction sequence,the Product $'C'$ is

Acetal or ketal is:

From the compounds given below,the number of compounds which give a positive Fehling's test is:
Benzaldehyde,Acetaldehyde,Acetone,Acetophenone,Methanal,$4$-nitrobenzaldehyde,cyclohexane carbaldehyde.