Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to choose a puppy by temperament [title] Learn all you can about the different temperaments puppies can have. [step] In general, puppies are classified as responsive, nervous, aggressive or independent. [substeps] A responsive puppy is adaptable and binds well with humans, which makes it a good choice for a first-time dog owner.

Ending1: A defensive puppy displays aggression, swings her tail, and yaws to no one. These impulsive behaviors are dangerous and could cause injury to the family member or friend. Ending2: A nervous or shy puppy is unpredictable, and not a good choice for families with children or other busy households. An aggressive puppy is dominant, sometimes unpredictable and does best in a household without children or other pets. Ending3: These cannot be treated as dangerous, aggressive, or threatening because of these restrictions. Since these restrictions apply to most dog breeds, a loyal, impulsive, energetic, inquisitive and vigorous breed is ideal. Ending4: A shy, nervous, adventurous and outgoing puppy is good for a first-time owner. Stubborn or anxious, active or stubborn dogs make excellent breeding partners, with a wide variety of personalities and temperaments.

Answer format: ending1/ending2/ending3/ending4