What Evidence Did Herczeg, Gonda, and Merilä (2009) Use to Suggest

What evidence did Herczeg, Gonda, and Merilä (2009) use to suggest that sticklebacks suffer a cost of sociality?

A) Fish raised in groups took longer to find food.
B) Fish raised in groups suffered higher incidence of disease.
C) Fish in groups had lower growth rates than fish raised alone.
D) Fish in groups experienced a higher cost of movement.
E) Fish in groups had a more restricted diet than did solitary fish.