Check all that are true:

a. To use fscanf or textscan, every line in the file must have the same format.
b. The name "fid" is just a variable name; you can call it anything you want.
c. All input functions (textscan, fscanf, and fgetl) must be in a while loop that repeats until the end-of-file is reached.

To use fscanf or textscan, every line in the file must have the same format  ( A

Explanation:

The fscanf and textscan is used to read lines in a file and to interpret with the format specified. hence every line in the file must have the specified format in order for the fscanf and textscan to read the lines. if any line lacks the specified format, then fscanf and textscan will only read the lines that matches and stop processing. option b is wrong because "fid" is an identifier and not just a variable name

while input functions (textscan, fscanf etc) are pre-defined input functions and must not be in a while loop infact they are used instead of a while loop.