Hi
Operations Vary but it would probably be the FO doing the flying under "monitored approach" procedures. - All the Fo will ever do is go around while the Capt is able to concentrate on getting the required visual refs for landing. Cat 2 minima is usually 100 ft 300 RVR. 3a is 50 / 200 while Cat 3 b is 14ft/75 m RVR. 757s are only normally 3B certified. Larger & other types go to cat 3 C which is 0/0 I believe.
Calls will be "Alert height" at Cat 1 minima "100 to go" at Cat 3 min +100ft ie 114ft and "decide" at mins or 14 ft. The response is "check" to all except the decide call when it is either "land" or "go around"
The GA from 14 ft will normally not result in a touch town but can do depending on weight Density Alt etc as already mentioned.
Our call was "Go around flap 15" positive climb by 3 different indications then "gear up" to acell alt normally 1000ft AAL then clean up as per normal.
Hope it helps
GG