Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to train a doberman pinscher [title] Get an appropriate collar. [step] A young dobie will not need much more than a collar. As your dog ages, however, you will notice its strength increase.

Ending1: For most females dogs this is not a problem, but for the deeper-chested males you may need to purchase a head collar. A head collar is best because it establishes dominance. Ending2: You may need a stronger collar, but you won't be able to train the dog unless you like having a collar in a larger size. [substeps] A good collar is about two-and three-quarter inches, which is the minimum size you will need for a young doberman pinscher. Ending3: This will depend on your dog's age. Older dogs will develop a collar of more than 150 millimetres. Ending4: Go to your vet for dog collar size recommendations. If you have a poor longterm training plan, you may need to try a more expensive collar.

Answer format: ending1/ending2/ending3/ending4