In a binary heap (array representation):

Parent(i) = \(\left\lfloor \tfrac{i}{2} \right\rfloor\),   Left(i) = \(2i\),   Right(i) = \(2i+1\)

All three can be computed directly from the index i.

But the heap size depends on the total number of elements \((n)\), which cannot be determined from i alone.

\(\therefore\) Correct Answer: (2) Heap size