Answer:
E. Both B and D would work
Explanation:
One of the major synthetic routes to produce ketones from alkynes involve the reactions known as oxomercuration and hydroboration.
Oxomercuration involves reacting the alkyne substrate with mercuric sulphate and sulphuric acid followed by reaction with H^+ from water.
Hydroboration involves reaction of the alkyne substrate with a molecule of the sort HB(R)2 followed by addition of alkaline hydrogen peroxide.
In both cases the starting material should be the 4-octyne.
