Which of the following path ways produces 2-hexanone
(i) 1-hexyne is treated with `H_(2)SO_(4), HgSO_(4)` and water
(ii) 3-methyl-2-heptene is treated with `O_(3)` followed by hydrolysis
(iii) n-butyl magnesium bromide reacts with acetaldehyde followed by hydrolysis and then chromic acid oxidation
(iv) hydroboration-oxidation of 1-hexyne.
A. `i`, ii and iii
B. `i` and ii only
C. `i` ii and iv only
D. `i` and ii only
