Which statement is correct?

a. A key distinguishing property of a data lake is that it stores raw data in its native format, which could be structured, unstructured, or semistructured.

b. A data lake is targeted toward decision-makers at middle- and topmanagement level, whereas a data warehouse requires a data scientist, which is a more specialized profile in terms of data handling and analysis.

c. In case of a data warehouse, the data schema definitions are only determined when the data are read (schema-on-read), whereas for data lakes they are fixed when the data are loaded (schema-on-write).

d. A data lake is less agile compared to a data warehouse, which has no structure.