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.
Thermal conductivity is not the answer for this question because it does not work
If you gave a little more information i could help you... which statements? is this a multiple choice?