Rapid Sequence Induction (RSI) is an anesthesia technique used to quickly secure the airway and is primarily indicated in situations where there is a high risk of aspiration. This usually involves patients who have not been fasting adequately or are at risk for vomiting and aspiration of gastric contents during anesthesia induction.

1. Emergency surgery for intestinal obstruction: Patients with intestinal obstruction are at a high risk of aspiration because they often have full stomachs and gastrointestinal fluids back up into the stomach. In such emergency situations, RSI is crucial to rapidly secure the airway and minimize the risk of pulmonary aspiration. Therefore, this is the correct indication for RSI.
2. Elective open hernia surgery: For elective surgeries, the patient is usually well-prepared, having fasted properly before the procedure. The risk of aspiration is minimal, and standard anesthesia induction techniques can be safely used. RSI is usually not required.
3. Cardiopulmonary bypass surgery: Although a complex procedure, this is typically elective or scheduled, allowing for adequate patient preparation and fasting. The need for RSI would depend on the patient's specific risk of aspiration which is generally managed otherwise unless specific contraindications exist.
4. Elective laparoscopic surgery: Similar to other elective procedures, patients are adequately prepared with fasting. Therefore, the risk of aspiration is low, and RSI is generally unnecessary unless there are specific risk factors present.

In conclusion, the indication for Rapid Sequence Induction is established by assessing the need to quickly and safely secure the airway in patients with a high risk of aspiration. Thus, the correct answer is the first option: Emergency surgery for intestinal obstruction.