The correct answer is: B. Data type of the variable.
The size of the memory space allocated for a variable depends on the data type of the variable. For example, a variable of type int will be allocated 4 bytes of memory, while a variable of type float will be allocated 8 bytes of memory.
The length of the variable name does not affect the size of the memory space allocated for the variable. The location of the variable in the program also does not affect the size of the memory space allocated for the variable. The size of memory in the computer is not relevant to the size of the memory space allocated for a variable.
Here is a table that shows the size of memory allocated for different data types in C++:
| Data type | Size of memory allocated (in bytes) |
| — | — |
| bool | 1 |
| char | 1 |
| short int | 2 |
| int | 4 |
| long int | 8 |
| float | 4 |
| double | 8 |
| long double | 12 |
I hope this helps!