Which of the following sampling plans for estimating the proportion of all adults in a medium-sized town who favor a tax increase to support the local school system does not suffer from undercoverage bias?

(a) A random sample of 250 names from the local phone book

(b) A random sample of 200 parents whose children attend one of the local schools

(c) A sample consisting of 500 people from the city who take an online survey about the issue

(d) A random sample of 300 homeowners in the town

(e) A random sample of 100 people from an alphabetical list of all adults who live in the town