The given diagram shows a destarched, variegated leaf, partly covered by black paper. The plant is placed in bright light for several hours.
Four discs are then cut from the leaf in the positions shown and are tested for starch. Which discs do/does not contain starch?
A 1, 3 and 4 only
B 1 and 2 only
C 2 only
D 3 and 4 only