Final answer:
The correct answer is b. edge gradient. An edge gradient artifact is a streak artifact that occurs when there is a high spatial frequency interface between tissues with a significant difference in density.
Step-by-step explanation:
The correct answer is b. edge gradient. An edge gradient artifact is a streak artifact that occurs when there is a high spatial frequency interface between tissues with a significant difference in density. This artifact is caused by the abrupt change in density along the edge of tissues. The difference in density creates an interference pattern, resulting in alternating bright and dark fringes, similar to an interference pattern formed by waves.