That's odd. The printed book says A and F are correct. (D is clearly wrong). Can you look at the answer text. Mine has this as the second stence "C, D and E are incorrect because the variable e is already in use from the lambda and cannot be redefined."
Granted that's not all that's wrong with it, but it is enough to rule out the answer choice.
Thanks for confirming, Jeanne! It seems I'm looking at an outdated version then. The online test and my Kindle book say
A, D, F. B is incorrect because it does not use the return keyword. C and E are incorrect because the variable e is already in use from the lambda and cannot be redefined. Additionally, C is missing the return keyword and E is missing the semicolon. A, D, and F are the only correct lambda expressions that match the functional interface.
I bought the Kindle book this year on January 6, 2019 via www.amazon.co.uk, so it should be a recent version. Anyway, thanks for the help.