In both sexes of cockroach, a pair of jointed filamentous structures called anal cerci are present on

Correct answer is option (1), because in both sexes of cockroach, $10^{\text {th }}$ segment bears a pair of jointed filamentous structures called anal cerci. Options (2), (3) and (4) are incorrect because $5^{\text {th }}, 8^{\text {th }}$ and $9^{\text {th }}$ segments do not bear such structures. In adult cockroaches only $10^{\text {th }}$ segments are present in abdomen. $11^{\text {th }}$ abdominal segment is absent.