The Termite Gut Protist Mixotricha Paradoxa Has at Least Two

The termite gut protist Mixotricha paradoxa has at least two kinds of bacteria attached to its outer surface. One kind is a spirochete that propels its host through the termite gut. A second type of bacteria synthesizes ATP, some of which is used by the spirochetes. The locomotion provided by the spirochetes introduces the ATP-producing bacteria to new food sources. Which of the following terms is (are) applicable to the relationship between the two kinds of bacteria?
1) mutualism
2) parasitism
3) symbiosis
4) metabolic cooperation

A) 1 only
B) 1 and 2
C) 2 and 3
D) 1, 3, and 4
E) 2, 3, and 4