It is great that you are paying attention to "and" while keeping an eye out for sufficient and necessary conditions. It won't hurt you to diagram it that way for this question, but I will show you why it is not necessary.
Let's assume that freedom of thought and expression is one item, FTE.
Premise: If society encourages FTE, then creativity will flourish (CF).
FTE - - - - - - - - - - > CF
Conclusion: Creativity flourished in the 18th century. Therefore, freedom of thought was encouraged in the 18th century.
CF - - - - - - - - - - - > FTE
This question makes the classic mistake of switching its sufficient and necessary conditions. Whether or not we diagram the "and", we have still identified the reasoning error that we can look for in the answer choices.
Let's diagram the "and" like you were inclined to do. Freedom of thought (FT) and freedom of expression (FE).
Premise: FT and FE - - - - - - - - - - - - - > CF
Conclusion: CF - - - - - - - - - - - - - - > FT
This is still the same error in reasoning. No matter which way you diagram it, you can get to the right answer. I agree with you that leaving out the expression part during the conclusion made things confusing. I'm not sure why they chose to word it that way. Normally, you will want to diagram the "and." This is kind of a weird question.
