Identify the sampling issues that are problematic in online surveys:
A. Many people use more than one internet service provider.
B. Every person has only one (unique) email address.
C. A house hold many have one computer but several users.
D. Internet users are a biased sample of the population.
Choose the correct answer from the options given below:

Correct option is D

The correct answer is A,C, and D only. Many people use more than one internet service provider (ISP): This doesn't directly affect sampling. It might influence how someone finds the survey but doesn't impact who participates. Every person has only one (unique) email address (Not true): People can have multiple email addresses, and this isn't a major sampling issue. A household may have one computer but several users (True): This is a concern. With one computer, only one person might participate, even if others in the house are eligible. Internet users are a biased sample of the population (True): This is a major issue. People without internet access can't participate, leading to a biased sample.
Therefore, options A, C and D are problematic for online surveys as they can lead to sampling bias.