In general, most data scientists will not add their data directly to body of their R or Python code. Instead, data scientists will "call" or "pull" the data into the programming using algorithms. Which of the following is most likely to disrupt this "calling" or "pulling" data step?

Using string data instead of numerical data

Having too many variables in the data files

Using Csv files instead of dat files

Inconsistently naming the files containing the data.