求教prep一逻辑~

sdcar2010

The premises: 1) Tranquilizer used during recollarization: Recollared --> tranquilizer used
2) Recollared females have low fertility. Recollared --> low fertility
The conclusion: some substance in the tranquilizer inhibits fertility: tranquilizer used  --> low fertility

For this argument to hold, the assumption is that NOTHING other than the tranquilizer can cause low fertility.

C is the answer since
1) If further evidence shows that never-recollared females who have been tranquilized also have low fertility, then the argument is strengthened.

2) If futher evidence shows that never-recollared females who have been tranquilized do NOT have low fertility, then the argument is weakened.

sdcar2010

C) How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars?

If we know that the tranquilizer is never used other than collarizing rhinos, the argument is valid.

However, if we know that the tranquilizer is used in other situations on female rhinos, plus the info from the stimulus that these affected female rhinos do not have low fertility rate, then the argument that the tranquilizer causes low fertility in female rhinos will be in trouble.

Therefore, whether tranquilizer is used in other situations is an important information to have for the evaluation of the argument.

As to the strenthening or weakening aspect, you have to look at the conclusion, which links the tranquilizer to low fertility. If new findings add more weight behind the conclusion, it's a strengthener. If new finidings cast doubt on the conclusion, it's a weakener.