A manager of a condominium wants to find out if the residents were satisfied with last year's maintenance of the building. He sends an e-mail survey to all the 400 residents. 10% of the residents answer the e-mail survey. Of those who answered, 60% indicated that they were satisfied with last year's maintenance of the building.

This type of survey suffers,mostly, from which of the following?

a) response bias

b) probability sampling

c) undercoverage

d)nonresponse bias