To solve this problem, we need to identify the structures responsible for excretion in cockroaches. Let's analyze each option:$\newline \bullet$Phallic gland: This gland is involved in the reproductive system of male cockroaches and is not related to excretion.$\newline \bullet$Urecose gland: This is not a recognized gland in cockroaches related to excretion.$\newline \bullet$Nephrocytes: These are cells in cockroaches that help in the filtration and removal of waste products from the hemolymph, contributing to excretion.$\newline \bullet$Fat body: This structure in cockroaches functions similarly to the liver in vertebrates, storing nutrients and detoxifying waste products, thus playing a role in excretion.$\newline \bullet$