[A]: The far-red form of the phytochromes ab- sorb light at 740 nm.
[R]: The red form of phytochrome absorbs light at 660 nm
A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false