How to save certain parts of cleaned data from Excel Spreadsheet?

What I have so far is:

filename = 'quiz_results.xlsx';
sheet = 1;

[nums,txt,raw] = xlsread(filename);
[nums1,txt1,raw1] = xlsread(filename,sheet,'G2:W2');
[nums2,txt2,raw2] = xlsread(filename,sheet,'B3:B103');

answerKey = txt1;
studentID = txt2;

[nums3,txt3,raw3] = xlsread(filename,sheet,'E3:E103');

essay = nums3;

[nums4,txt4,raw4] = xlsread(filename,sheet,'G3:W103');

multipleChoice = txt4;

save('filename.mat',answerKey,studentID,essay,multipleChoice); % this is resulting in an error saying "Error using save
Must be a string scalar or character vector."

I would only like to save the new data I collected which is "answerKey, studentID, essay, and multipleChoice". How do I do this? Thank you!

Answer 1

[Walter Roberson]

save('filename.mat', 'answerKey', 'studentID', 'essay', 'multipleChoice');