Answer:
First, the options:
A. Midazolam
B. Ketamine
C. Nitrous Oxide
D. Bupivacaine
The ANSWER is A. 
A. Midazolam
Explanation:
A. Midazolam✔
Midazolam is mainly used for amnesia or sedation in many diagnostic, therapeutic, and endoscopic activities or procedures. 
B. Ketamine ❌
It has higher risk of side effects. 
C. Nitrous oxide ❌
It won't be preferable for this case, since it can not be breathed in during a bronchoscopy. 
D. Bupivacaine❌
This is solely for local anesthesia.
 
        
             
        
        
        
To make ATP, cells must join together ADP & a phosphate using energy from food. A phosphate is removed from an ATP molecule in order to provide energy for the cell. Thus, the ATP molecule turns into an ADP molecule. We eat food which gives us energy to add another phosphate group to the ADP molecule, turning it into an ATP molecule. The cycle then begins again.