How to copy contents of multiple files pre-selected into one file?

Question

linux

Hello! Suggest the best solution.
You need to copy content from files of a specific extension to a separate file. The files are in different folders.

Answer 1

find . -name *.c -exec cat {} \; >> destination

Answer 2

A script that contains all the paths to these files.

Answer 3

cat /home/user/file1 >> /home/user/file
cat /home/user/file2 >> /home/user/file
cat /home/user/file3 >> /home/user/file

Answer 4

find. -name *.c | xargs cat > output_file