It would not be plants, even though it has cell walls. They are not made of chitin. Plants are also not heterotrophic.
Fungi, however, decompose other matter, and have cell walls made of chitin. This would fit the description.
I believe the answer is C) is different lengths of time for different types of cells.
The reason is to help in seed dispersal. Seed dispersal is the movement or transport of seeds away from the parent plant. Due to the fact that plants have very limited mobility they have to rely upon variety of dispersal; vectors to transport their seeds, including both abiotic and biotic factors. Seed dispersal is important because if seed are not dispersed, many germinating seedlings will grow very close to the parent plant which would result to competition between every one of the seedlings as well as the parent. The competition for essential growth factors such as light, space, water and nutrients.
The speed of a longitudinal wave will not be affected by the temperature of its surrounding. Base on the formula for the wave speed (applicable on longitudinal wave), wave speed ( speed in m.s 2) is equal to the distance of a wave (wavelenth in meter) travel over a unit of time (seconds) or wave speed is equal to distance of a wave times the frequency (hertz), temperature is not included in calculating the wave speed.