Answer the following question given this paragraph: Figure 34.12 (a) Light from a distant galaxy can travel different paths to the Earth because it is bent around an intermediary galaxy by gravity. This produces several images of the more distant galaxy. (b) The images around the central galaxy are produced by gravitational lensing. Each image has the same spectrum and a larger red shift than the intermediary. (credit: NASA, ESA, and STScI). Q: Light from a distant galaxy can travel different paths to the earth because it is bent around an intermediary galaxy by what? A:

Choices: (I). radiation; (II). strength; (III). variation; (IV). gravity;
The answer is:
(IV).