Researchers have found that when habitual smokers are provided with low-nicotine cigarettes they:
a) smokers commonly report that smoking reduces stress.
b) adult smoking increases with stress.
c) smokers feel much more relaxed than nonsmokers do.
d) smokers report less anxiety if allowed to smoke.

Option 1 is the answer - smoke more to maintain their nicotine intake

Explanation:

Nicotine is a highly addictive component of tobacco that leads to the continuous smoking of cigarette by habitual smokers. When nicotine obsession develops, it becomes very difficult to refrain from the use of tobacco products by addicted individuals.

Experimental studies on reduced nicotine content cigarettes have shown that when chain-smokers are presented with low nicotine cigarettes, they tend to adjust their smoking habits so as to maintain the amount of nicotine intake they need.

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals