How do you know if blogging is for you ? and as a student what are my topic options ?

Short answer: Write about what interests you.
Long answer: As a business major, you have many avenues you may choose to pursue. As a blogger, you are sharing expertise, insights and advice with others. So you must first obtain expertise and have experiences (or complete case studies) that lead to insights and advice.
You may choose to blog about business topics that you are currently studying in a class. In this case, your research on a topic works two-fold. Blogging may also help you to find what you do and do not enjoy in the world of business. For example, you may think yourself highly interested in business technology. You read some Bloomberg Business or The Economist articles and find yourself amazed, disinterested, or somewhere in between. If you are amazed, you may decide to research a particular product or strategy then find yourself with the expertise to write a blog post about that topic.
Blogging is essentially writing about what you know and learn. The best thing you can do is write about topics about which you are passionate- business or otherwise. You may find personal fulfillment and you will sharpen your writing skills.

Any type of on-line discussions should be treated with the same constraints as social media in general. You would need to identify your target market then look for blogging sources that would be best suited for the best blog possible. Make sure to research the blog source and find a reputable company with a proven track record. The blog is a great tool to reach perspective clients or have an open forum discussion on topics that interest you. You must again be careful as to what you post and how you present it-nothing that could be used to steal your identity and nothing that would offend to the point of exposure to legal penalties. If you do your homework and hold true to what is most important in discussing topics blogging can be a great tool. Good luck.