Final answer:
The memory reserved for a compound data type in C is determined by the size and composition of the type, which can encompass multiple member types and sizes.
Step-by-step explanation:
The number of memory boxes reserved for a compound data type in C depends on the size of the compound type. Compound data types, such as structs and unions, can contain multiple members, each of which may be a different type and size. The total amount of memory allocated is the sum of the sizes of each member, potentially adjusted for any padding or alignment requirements imposed by the system. As a result, the memory reserved can vary widely.