B. Studies suggest that touching, like food and shelter, is key to normal mammal development.
<h3>Explanation:</h3>
Choose the implied <u>main idea</u>.
A. Baby mammals need to be given food and shelter.
This is a concept of the text, but this idea is introduced not as an idea, but really to introduce their own argument. They're basically saying, "Although baby mammals need food and shelter, <u>(key concept)</u>."
B. Studies suggest that touching--like food and shelter--is key to normal mammal development.
This is definitely a key concept of the text. This can be seen by the fact that the author focus their main argument, background knowledge, and evidence on the idea that newborn mammals are affected by a lack of contact with others.
C. All animals who are raised without physical contact with other animals develop strange habits.
Focus on the wording I bolded, and make sure you watch out for strong, blanket statements like this one. This text is focusing not on all animals, but specifically mammals like monkeys.
D. Scientists have done studies of monkeys raised without physical contact with other animals.
This is true, but is a summary of the text instead of breaking down the article and its purpose. Watch out for trick questions where you give a correct answer, but incorrect in the context of the question.
THe answer is A. Themselves. A reflexive pronoun indicates that the person who is realizing the action of the verb is also the recipient of the action.