Solution

In a heap (implemented as an array), given the index i of a node:

• The parent index can be calculated as \( \text{Parent}(i) = \lfloor i/2 \rfloor \) (for 1-based indexing) or \( \lfloor (i-1)/2 \rfloor \) (for 0-based indexing).
• The left child index can be calculated as \( \text{Left}(i) = 2i \) (1-based) or \( 2i+1 \) (0-based).
• The right child index can be calculated as \( \text{Right}(i) = 2i+1 \) (1-based) or \( 2i+2 \) (0-based).

However, the heap size is not computable from the index of a node alone; it is stored separately.

Answer: Option B → Heap size