Concept:The gender split of the 16 participants who left is not given, so the final ratio alone cannot determine the initial total.Explanation:Let initial male participants be 3x and female participants be x.So, initial total =3x+x=4x.Suppose a male participants left during the tea break.Then female participants who left =16−a.After 6 more female participants registered:Male participants =3x−aFemale participants =x−(16−a)+6=x−10+aGiven final ratio is 2:1, we get:x−10+a3x−a​=12​3x−a=2x−20+2ax=3a−20So, initial total =4x=12a−80.Since the value of a is not known, the initial total cannot be uniquely determined.Answer:D. Data Insufficient