Could you please clarify what do you mean by positive argument?
This question asks us to find a logical structure most like that of the argument presented. The argument is structured as follows:
Full-term babies (B) are born with reflexes that disappear by age of two months (R). Because this 3-month old exhibits such reflexes, this baby is not a normal full-term baby.Note that conclusion is a contrapositive of the premise , which makes it a logically valid argument.
I am going to use "~" for not to diagram the argument, B for "baby" and "R" for reflexes.
B -> ~R
The premise essentially says that IF it is a full-term baby, THEN after 2 months there are NO reflexes.
R -> ~B
The conclusion says that IF there are reflexes in a 3-month old, THEN it is NOT a full term baby.
The correct answer choice D follows the exact same reasoning.
Because opossums (O) have abdominal pouches (P) and this animal lacks any such pouch, this animal is not an opossum.
Let's diagram this argument.
O ->P
IF the animal is an opossum, THEN it has a pouch.
~P -> ~O
IF the animal does NOT have a pouch, THEN it is NOT an opossum.
Let me know if this is helpful and if you have any more questions.
rzamor87July 17, 2019
Thank you for following up. I was able to get the correct answer but upon hearing the explanation I overheard a positive logical argument. I just wondered if there was an explanation for that.
