Final answer:
The exact number of genes in the file cannot be determined based on the given information.
Step-by-step explanation:
According to current estimates, humans have around 20,000 to 22,000 genes. However, the question does not specify if it refers to human genes or genes in general. Therefore, we cannot determine the exact number of genes in the file based on the given information. Without more context, it is not possible to choose any of the given options (a, b, c, d) as the correct answer.