Deciduous plants lose their leaves each year in response to changes in the day length.The biorhythm exemplified in the given statement is

Explanation

The correct answer is Option B: circannual rhythm. This is because deciduous plants lose their leaves once a year, which aligns with the annual cycle characteristic of circannual rhythms.Option A, circadian rhythm, is incorrect because it involves daily cycles. Option C, circatidal rhythm, is incorrect because it involves tidal patterns, typically occurring multiple times a day. Option D, circalunar rhythm, is incorrect because it involves monthly cycles related to the lunar phases, not annual changes.