AP Biology help?

This is the question:


While studying the plant Arabidopsis, a botanist finds that an RNA probe produces colored spots in the sepals of the plant. From this information, what information can be inferred?


A. The differently colored plants will attract different pollingating insects.


B. The RNA probe is transported only to certain tissues.


C. The colored regions were caused by mutations that occurred in the sepals.


D. The RNA probe is specific to a gene active in sepals.


E. More research needs to be done on the sepals of Arabidopsis.


Serious answers only, please!

AP Biology help?
D. All cells in the plant should have the same DNA (ignoring randomly scattered mutations). However, the DNA is only used for transcription (conversion into RNA) in places where the gene is active. In the places where the gene is active, the RNA will be used for translation, allowing the corresponding proteins to be formed.
Reply:I think it is D. The RNA probe will bind to its complementary DNA and produce color when developed (given that the probe is labeled, either fluorescent or radioactive). If the complementary DNA is found in the sepals, you will see color spots in the sepals.
Reply:Not 100% sure, but have taken AP bio in high school too.





I'm thinking it's D.