Which of the follwoing demonstrate a downside of crowdsourcing?

Crowdsourcing is a practice wherein a person or group or person engage a crowd or group for a common goal for the purpose of innovation, problem solving or efficiency. New technologies, social media and web 2.0 are used in crowdsourcing. The following are the disadvantages of cowdsourcing: (1)Confidentiality and security. This is the deadliest disadvantage of crowdsourcing. It is essential to keep certain things from competitors but in crowdsourcing, you are dealing with large and anonymous group of people in there may be a malefactor or a direct competitor. (2) Communication. It can be difficult due to time and language barriers. (3) Management. There is an increased need of management because it will mean dealing with a large number of people. (4) Approach. Crowdsourced people may not be as serious or interested. They may not be paying very close attention because they are deeply involve in the project. (5) Quality. There is no guarantee that the result will be of sufficient quality or effective. Some of the respondents may cheat because some of them may just submit copied or plagiarized ideas

The answer would be sand and gravel