The most appropriate data type for the field holding the count of units in an apartment building would be a numeric or integer data type. Option a is the right choice.
The most appropriate data type for a field that holds the count of the number of units in an apartment building would be a. numeric or integer. This is because the count of units is a discrete, whole number value that does not require decimal precision or currency formatting.
Option b. currency would not be suitable as it is meant for storing monetary values, while the count of units is a non-monetary quantity.
Option c. sequence or autonumber is also not appropriate as it is typically used for generating unique identifiers, whereas the count of units is a straightforward numerical value.
Option d. calculated is not applicable in this case as the count of units is a direct and measurable quantity that does not require any calculations.
Therefore, the most suitable data type for the field holding the count of units is numeric or integer.
Option a is the right choice.