Toxicology major

Hi, I have a bachelor degree in chemistry and planning on taking master's degree in toxicology. I need an opinion from anybody here who's a toxicologist. I found out that I have to choose the concentration (such as pharmaceutical chemistry, clinical toxicology, forensic toxicology, and many more). Aside from what I like and interested in, which concentration do you think is the most promising in terms of workforce? Thank you!