Final answer:
D) Only people that have and know how to use a computer can participate is not an advantage of online focus groups; it's a disadvantage that limits the participant pool. Other options A, B, and C are advantages.
Step-by-step explanation:
The question pertains to the advantages and disadvantages of online focus groups. Of the options provided, statement D) Only people that have and know how to use a computer can participate is NOT an advantage of online focus groups. It is, in fact, a disadvantage as it limits the participants to only those who have access to and are proficient with technology.
Online focus groups do offer advantages by allowing researchers to reach segments that are usually hard to survey (A), they enable researchers to re-contact participants (B), and are generally more cost-effective than traditional face-to-face focus groups (C). However, they can be susceptible to issues such as multiple responses from the same individual, misrepresentation of demographics, and difficulties in achieving a representative sample, making it challenging to generalize findings to the broader population.