Duolingo translated the Frech word sensible as sensitive. That is not correct, I think.
Sensible has to do with the mind. You can replace it with raisonnable. Sensitive has to with feelings. You can replace it with susceptible, impressionnable.
At least, that is what I think of it. What is your opinion?
The French word "sensible" can be translated as the English word "sensitive". We can be "sensible" (FR) in mind or body, Il a le cœur sensible - mind, il a la peau sensible - body.
It is one of the classic "faux amis", words that sound as if they have the same meaning but don't. Here is a link about them: http://french.about.com/od/vocabulary/a/fauxamis.htm
Two hundred years ago "sensible" in English meant the same thing as the modern French "sensible" or modern English "sensitive". It is English that has changed. Hope this helps.
Be careful with this kind of reasoning. I'd say at least look it up in a dictionary before you accuse Duolingo of getting it wrong.
I see this most often on French skin products like sun screen. Often marked as suitable for "peau sensible" - sensitive skin. It is, as Mizotte says, a false cognate.