Fact 1: Plants detect and respond to the daily cycle of light and darkness. Fact 2: Diurnal cycles Diurnal cycles are the daily cycles of light and darkness. Given the two facts above, what detect and respond to diurnal cycles?

pick from the following.
(a). tides
(b). stars
(c). fens
(d). Oak
(e). Conifers
(f). humans
(g). water
(h). plants
The answer is:
(h).