Answer: It is important to conduct multiple trials so one can get the best results, additionally, multiple trials with result in minimal errors. Finally it is important to conduct multiple trials because it will show you the actual answer/solution/whatever. If you do something once their may of been a random unknown affect and you would of never knew because you only conducted the experiement once.
Explanation:
In the reactants Sb has oxidatin number 0 (because it is in its elemental form)
In the products Sb has oxidaton number +3.
Then Sb lost electrons which means it oxidized.
C. K since it is above Aluminium in the reactivity series