bizneznuz.com, an online business news agency, conducts a poll. Visitors to the site are invited to click on one of two buttons in order to register that they "agree" or "disagree" with the following statement: "Funding for space exploration should be left entirely to the private sector."

If bizneznuz.com wants to accurately measure its online readership's support for government-funded space exploration, this poll will deliver a biased and unrepresentative response because:

Select one:

a. The pool of respondents is self-selected.

b. All respondents have internet access.

c. bizneznuz.com targets mainly the business community.

d. All of the above.