Two main steps are applied in snowball sampling method. The potential members in the population are identified. Then, some of the members are selected initially. The identified subjects are asked to recruit other members and then those people are asked to recruit, and so on. However, the selected participants should be made aware that they do not have to provide any other members. The above steps are repeated until the determined sample size is achieved. Ethically, the identified members should not be forced to give other members. Rather, the previously identified members should be asked to encourage others to participate. The correct answer is A.