I want to know the answer to the following question:
Who was the Grand Secretary under Jiajing?
All the background I'm provided with is that "Grand Secretary Yang Tinghe under Jiajing was determined to break the eunuch influence at court which typified the Zhengde era, an example being the costly escort of the eunuch Liu Yun as described above in his failed mission to Tibet.". Is that enough to answer the question?
Answer: yes