The fact that you are more likely to earn more money over your lifetime with a post secondary degree means...

a. the more money you pay for the degree guarantees a higher salary.
b. the cost of a post secondary degree should be avoided.
c. the cost of a post secondary degree is worth it.
d. you should not be concerned about the amount of debt you go into to pay for it.

c.the cost of a post secondary degree is worth it.

Explanation:

The statement indicates that if you have a post secondary degree you will be able to get more money during your life and from this, you can infer that the money you pay to receive this type of education would be worth because you will see the benefits in the future with higher earnings. According to this, the answer is that the cost of a post secondary degree is worth it.

The other options are not right, because the statement only says that you will get more money if you have a post secondary degree than if you don't get it but it doesn't indicate that if you pay more for it you will earn more. Also, as you will get more money, you shouldn't avoid getting one and you can't infer from the statement that you shouldn't care about the amount you will spend to get the degree.

definitely a