Answer:
A. Yes.
B. No.
Step-by-step explanation:
A. Is abstinence the only 100 percent effective way to protect against pregnancy?
Yes, if we look for a 100% effective way, abstinence is the only way, because other contraceptive doesn't have 100% of effectiveness, there's a chance to get pregnant. But, if people don't have sexual intercouse at all, there's no way to get pregnant.
B. Are spermicidal methods of contraception more effective than hormonal methods?
No, actually, spermicidal methods or spermicides constitute the least effective contraception method. However, it's better than no method at all, but if the person has the possibility to choose another method, it'll be better, because the presence of spermicides even with condoms, it hasn't proved any improvement as contraceptive method.