Which of the Following is NOT a Member of the Deltaproteobacteria

Question

Which of the following is NOT a member of the Deltaproteobacteria?
A) Campylobacter
B) Desulfovibrio
C) Geobacter
D) Syntrophobacter

Accepted Answer

Campylobacter belongs to the Epsilonproteobacteria, not the Deltaproteobacteria.