I want to know the answer to the following question:
What subject did Avicenna start studying at 16?
All the background I'm provided with is that "The teenager achieved full status as a qualified physician at age 18, and found that "Medicine is no hard and thorny science, like mathematics and metaphysics, so I soon made great progress; I became an excellent doctor and began to treat patients, using approved remedies."". Is that enough to answer the question?
Answer: no