Hi, Florence! These are great questions – thank you for writing them out so clearly! You are correct that in these questions Fu Zi and Rou Gui (I am assuming you meant Rou Gui and not Gui Zhi) are extremely similar – we are splitting hairs here, really! For the first question, you are absolutely right that both Fu Zi and Rou Gui are indicated for Heart Yang Deficiency. Here I would choose Fu Zi over Rou Gui because Rou Gui is more known for warming the Kidney / Mingmen Fire so in terms of strength to treat the Heart Yang Deficiency, Fu Zi will be stronger for these symptoms. For the second question, this is almost verbatim from the Bensky Materia Medica book that Fu Zi is for Wind-Cold-Dampness Bi Zheng with a predominance of Cold whereas Rou Gui is for Cold-Dampness Bi Zheng. Likely you immediately ruled out the other two options in both of these questions, and often that is how multiple choice questions go – rule out two options quite easily and then split hairs between the remaining two (I am trying to have you become experts at that in these questions!), but I agree with you that these are really close! I will consider editing these questions for a bit more clarity, but sometimes hard questions make for great learning so I am glad we had this discussion! Thank you so much for bringing them to my attention!