Although It Is Often Difficult to Estimate How Many Youth

Although it is often difficult to estimate how many youth are involved in the sex trade industry, Goldenberg et al. report that ________ per cent of sex workers initiate sex work as adolescents.

A) 5 to 10
B) 10 to 20
C) 20 to 40
D) 30 to 50
E) 40 to 60