When Derek writes his autobiography, he can just concentrate on recalling the events he experienced in the past, without thinking about the keystrokes he needs to hit. He uses in recalling the past events, and in hitting the right keystroke.

The correct answer to this open question is the following.

Although there are no options attached, we can say that when Derek writes his autobiography, he can just concentrate on recalling the events he experienced in the past, without thinking about the keystrokes he needs to hit. He uses explicit memory in recalling the past events, and implicit memory in hitting the right keystroke.

Scholars consider that you use explicit memory when people have to make a conscious effort to remember something. For instance, if you try to remember your friend's names from elementary school, you have to use explicit memory to make an effort and try to name some of your friends at that time.

On the other hand, when data, names, figures, or any information comes up easily to your mind, then it is said that you use your implicit memory. Ideas and memories easily come to your mind.