Answer:
B. save your document frequently
Step-by-step explanation:
Saving your documents time to time will prevent loss of work on computer which could be possible due to different reasons like electricity off, some wiring issue or even hardware/software of computer could be hanged.
So saving frequently can save your work also it is best practice to save in different name so that older history is maintained.
New solution to these problems are using cloud based documents those auto save your work and also maintain history.