Hello,

data warehousing is the root stream of data science while option 1 and 2 are project work which is done based on many concepts like Machine learning, Data analysis , Data visualization. each domain has it's own streams.

financial modeling and forecasting is a linear learning model which comes under super vised learning which has 7-8 algorithms in it while Medical image analytics is subset of Image retrieval /image processing.

so based on all the details, 3rd option will be best where you will learn basic concept of data science and use them while working on option 1 and 2.

Hope it helps!