Drop-down value selection in column A, automatically update next column value assigned it

How can I assign values/message to drop-down list? Once I select any value from drop-down list in Column A, I want next sell from Column B to be automatically updated with some value assigned to earlier drop-down value.

Like.

If below is my drop-down list from Column A from

1. Developer
2. Tester
3. Dev Lead
4. Test Lead

and below are the corresponding actions needs to be updated automatically in Column B as per the above selection

a) Need to learn new languages
b) Need to learn various test validation
c) Need to conduct training
d) Need to assign further test validation