He active ingredient(s) in tobacco that is addictive, colorless, and a highly volatile alkaloid is

The answer would be nicotine.

Nicotine is an addictive substance. The type of nicotine that is found particularly in tobacco is nicotiana tabacum. It comes from the nightshade family of plants. Other forms of nicotine can also be found in tomatoes, potatoes, green peppers, and eggplants. 

Im assuming this is a multiple choice answer what is the answers to chooce from?

The vascular system