Deciding whether a collection of sets is a partition

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Which of the following collections of sets is a partition of [0,∞)?

A. $S_i$ = (i-1,i) for i =1, 2, 3, …

B. $S_i$ = (i-1,i] for i =1, 2, 3, …

C. $S_1$ = (0,1], $S_i$ = [i-1,i] for i = 2, 3, 4, …

D. $S_1$ = (0,π], $S_2$ = (π,350π), $S_2$ = [350π,∞)

E. All of these

I'm having trouble answering this, I know what a partition is, however I'm having trouble with the notation of this problem... Is the the set [0,∞)= {0,1,2,3,4,5....}

For example, choice (A. $S_i$ = (i-1,i) for i =1, 2, 3, …) the sets would be

$S_1$ = (0,1), $S_2$ = (1,2), $S_3$ = (2,3)....

So are these sets disjoint, and additionally is the union of them equal to [0,∞)?

Thanks