In the past, every ten-percentage-point increase in cigarette prices in the country of Coponia has decreased per capita sales of cigarettes by four percent.Coponia is about to raise taxes on cigarettes by 9 cents per pack.The average price of cigarettes in Coponia is and has been for more than a year 90 cents per pack.So the tax hike stands an excellent chance of reducing per capita sales of cigarettes by four percent.
Which of the following is an assumption on which the argument depends?
Tobacco companies are unlikely to reduce their profit per pack of cigarettes to avoid an increase in the cost per pack to consumers in Coponia.
Previous increases in cigarette prices in Coponia have generally been due to increases in taxes on cigarettes.
Any decrease in per capita sales of cigarettes in Coponia will result mainly from an increase in the number of people who quit smoking entirely.
At present, the price of a pack of cigarettes in Coponia includes taxes that amount to less than ten percent of the total selling price.
The number of people in Coponia who smoke cigarettes has remained relatively constant for the past several years.
Mice that have been given morphine are very likely to develop blood poisoning because bacteria that normally reside in the intestine typically respond to morphine by migrating into the bloodstream.However, when mice are given both morphine and the new drug naltrexone, blood poisoning is much less frequent, although it does still occur.These results provide support for researchers’ prediction that naltrexone will turn out to be toxic to certain types of bacteria.
Which of the following, if discovered to be true, would most seriously weaken the support for the researchers’ prediction?
After being administered to mice, naltrexone does not pass from the bloodstream into the intestine.
Naltrexone inhibits morphine from triggering the migration of intestinal bacteria into the bloodstream.
Mice that have been given naltrexone but not morphine have no greater risk of developing blood poisoning than do mice that have not been given either substance.
The increased risk of blood poisoning is not the only harmful effect on mice of being given morphine.
Conditions other than the presence of intestinal bacteria in the bloodstream can cause blood poisoning in mice.