Answer:
d. Derek is hungry or needs to have his diaper changed.
Step-by-step explanation:
When we are only one year old, there are main reasons why we cry, one of them is because we are hungry. So, crying is our mecanism to communicate to our moms about our state, and one the most primitive is being hungry.
Additionally, a second reason why we cry at that age, it's beacuse we pooped, and we want to be clean again.
Therefore, the right answer is d.