A botanist exposed two groups of the same plant species to two photoperiods-one with 14 hours of light and 10 hours of dark and the other with 10 hours of light and 14 hours of dark. Under the first set of conditions, the plants flowered, but they failed to flower under the second set of conditions. Which of the following conclusions would be consistent with these results?

a. The critical night length is 14 hours.
b. The plants are short-day plants.
c. The critical day length is 10 hours.
d. The plants can convert phytochrome to florigen.
e. The plants flower in the sprin