To solve this problem, we need to identify which plant has a mutualistic relationship with a species of moth, where both the plant and the moth depend on each other to complete their life cycles.$\newline$Let's analyze the options:$\newline \bullet$Option 1: Banana - Bananas do not have a specific mutualistic relationship with a moth species for their life cycle.$\newline \bullet$Option 2: Yucca - Yucca plants have a well-known mutualistic relationship with the Yucca moth. The moth pollinates the flowers of the Yucca plant, and in return, the plant provides a place for the moth to lay its eggs. Both species depend on each other for reproduction.$\newline \bullet$Option 3: Hydrilla - Hydrilla does not have a specific mutualistic relationship with a moth species.$\newline \bullet$Option 4: Viola - Viola does not have a specific mutualistic relationship with a moth species.$\newline$Based on this analysis, the correct answer is Option 2: Yucca.$\newline$Yucca plants and Yucca moths exhibit a unique example of coevolution, where both species have evolved traits that benefit each other, ensuring their mutual survival and reproduction.$\newline$Therefore, the correct option is Option 2.