Given, functional dependencies are F={A→ BC, C→ D}
Finding candidate key of given relation is relation is
A+={A,B,C} because we don’t have an A element in right hand side.
A→ BC dependency A is the candidate key and also part of FD. So, it is lossless.
C→ D is following Transitive dependency. So, it never become 3NF.
According to given choices, A is the correct choice.