Answer:
C
Explanation:
By itself, spermicide prevents just 72% of pregnancies, the least effective of any major contraceptive measure. Because of its poor success rate, spermicide is often used in conjunction with other contraceptives such as patches and condoms.
Answer: 80-90%
Explanation: "Cigarette smoking is the number one risk factor for lung cancer. In the United States, cigarette smoking is linked to about 80% to 90% of lung cancer deaths. Using other tobacco products such as cigars or pipes also increases the risk for lung cancer." - cdc.gov
That is true according to the Yerkes-Dodson Law