Explanation:

- Alarm: This word can denote a warning of danger or a feeling of fear caused by the expectation of danger.

- Option 1: Wake: This usually means to awaken someone from sleep. It's loosely related but not the best synonym for alarm.

- Option 2: Ring: Often associated with a sound made by alarms, yet it is more about the action rather than the emotional or warning aspect that "alarm" conveys.

- Option 3: Sound: This is a general term for noise. It aligns with what an alarm makes but does not capture the sense of urgency or fear.

- Option 4: Panic: This refers to a sudden overwhelming feeling of fear or anxiety. This is very close to what someone may feel in response to an alarm.

Given the emotional and urgent nature of "alarm," Option 4: Panic is indeed the most suitable synonym.