Conclusion: they are unlikely to affect the problem that concerns citizens, since most crimes committed by local teenagers take place between 3 p.m. and 6 p.m.
Reasoning: The incorrect answers are ones that strengthen the answer choices or others that are neutral. Weakening the conclusion must attack the conclusion so as to prove that it's not likely crimes are committed between 3 pm to 6 pm (with the series of measures instituted)
A. Similar measure adopted in other places have failed to reduce the number of teenagers on the streets in the late evening Wrong - opposite answer; we need why the measures work. It's certainly a trap answer.
B. The crimes committed by teenagers in the afternoon are mostly small thefts and inconsequential vandalism. Correct - "serious" modifies the crimes, whereas the "small" and "inconsequential" modify most of the crimes that occur from 3pm to 6pm.
C. Teenagers are much less likely to commit serious crimes when they are at home than when they are not at home. Wrong - Neutral. Indeed teenagers can't commit serious crimes when they are at home.
D. Any decrease in the need for police patrols in the late evening would not mean that there could be more intensive patrolling in the afternoon. Wrong - opposite answer. This is opposite because the answer must weaken the conclusion that the measures are likely to succeed.
E. The schools in Parktown have introduced a number of after-school programs that will be available to teenagers until 6 p.m. on weekday afternoons. [color=#ed1c24]Wrong - this does not properly weaken the conclusion because we don't know if the teenagers will attend /color]
A little kudos never hurt anyone.