To solve the problem, we need to identify the part of the brain responsible for controlling emotions.
1. Understanding the Role of Different Brain Parts:
- The Cerebrum is involved in higher brain functions such as thinking, voluntary movement, and sensory processing but is not the primary control center for emotions.
- The Diencephalon, which includes structures like the thalamus and hypothalamus, plays a significant role in controlling emotions. The hypothalamus, in particular, is involved in regulating emotions, hormone production, and other functions related to emotional responses.
- The Midbrain is involved in functions such as vision, hearing, and motor control but does not primarily control emotions.
- The Cerebellum primarily controls coordination and balance and does not directly control emotions.
Final Answer:
The part of the brain that controls emotions is the $ {\text{Diencephalon}} $.