The single best way to increase your income is to get an education. why?
1- you automatically make more money if you are educated.
2- you automatically get promotions if you are educated.
3- you can obtain jobs that have higher starting salaries.
4- you will automatically receive better benefits. my answer is 3

3- You can obtain jobs that have higher starting salaries.

Explanation:

This is the most likely answer to the question. The reason why education is likely to increase your income is because it can give you access to jobs that have higher starting salaries. This puts you at an advantage compared to people who do not have the same level of education. Answers 1, 2 and 4 are not correct because education does not "automatically" give you anything. It only increases your chances of your income being a good one.