a. By leaving them in bondage to sin, unable to respond to God apart from his grace.

Step-by-step explanation

According to Augustine, the way sin has affected humans is by leaving them in bondage to sin, unable to respond to God apart from his grace.

Augustine believed that sin affects humanity by destroying the image of God in humanity. The ability for humans to be able to see and know God is destroyed when they turn away from God because of sin. When Adam and Eve chose to disobey God in the garden, it caused them to become separated from him. This separation causes them not only to be separated from each other but also from their own nature as image bearers of God.