An algorithm is designed to monitor a battery management system for an autonomous drone.

Figure 1 shows the pseudocode for this system.

1   voltage ← READ_VOLTAGE()
2   charge_state ← "DISCHARGING"
3   WHILE voltage < 12.6 DO
4       IF voltage < 10.5 THEN
5           charge_state ← "CRITICAL"
6           TRIGGER_ALARM()
7       ELSE
8           charge_state ← "LOW"
9       ENDIF
10      voltage ← READ_VOLTAGE()
11  ENDWHILE

Identify the line number where selection is first used in the algorithm shown in Figure 1.