Fairy, I Really Can Cure You

This world is home to demons, immortals, fiends, and sages.

Luo Qingnang wakes up in a brothel and nearly becomes a murderer. Thanks to the medical knowledge from his previous life, he manages to clear his name.

His master says, "Medicine is a good field. You can learn to heal the sick and save lives."

Luo Qingnang: "No, no. Cultivating immortality can let you live forever."

His master says, "Medicine is a good field. You can learn to become rich."

Luo Qingnang: "No, no. Become an official, and you can have wives and concubines galore."

His master says, "Medicine is a good field. You can earn people's respect."

Luo Qingnang: "No, no. Studying can change your fate."

His master: "Medicine is a good field. If you study it, I'll betroth your senior sister to you."

Luo Qingnang's eyes light up. "Is that a promise, Master? Please accept this disciple's bow!"

Should I start with molecular biology or cell biology?