Study the algorithm shown below.
1 salinityReadings ← [35.2, 34.8, 32.1, 35.5]
2 alertTriggered ← false
3 counter ← 0
4 WHILE counter < 4 AND alertTriggered = false
5 IF salinityReadings[counter] < 33.0 THEN
6 alertTriggered ← true
7 ELSE
8 counter ← counter + 1
9 ENDIF
10 ENDWHILE
State the data type of the variable alertTriggered in this algorithm.