Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to train a horse to trailer [title] Give the horse a bucket of treats each day. [step] Drop a few oats into a bucket and leave it at the horse's bedtime stall each morning. Repeat this for several weeks, to get the horse comfortable and excited when he sees the bucket.

Ending1: Have your horse make short trips using oats inside the bucket, until it's completely full. [substeps] You can also dry the bucket by blotting it with a towel each time you take it out of the bucket. Ending2: If he obeys quickly, praise him and engage with walking patterns. If he does not, give him treats (and praise) at the very moment he jumps up to get out of the bucket. Ending3: [title] Gradually move the bucket into the trailer. [step] After several weeks, place the now familiar treat bucket inside the trailer. Ending4: As the horse gets more comfortable with the bucket, gradually add more and more oats in a slow-tempo meowing cycle. [title] Provide several treats when the horse rears.

Answer format: ending1/ending2/ending3/ending4