Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to choose a sleeping bag for backpacking [title] Select a backpacking sleeping bag rated for temperatures you anticipate during your trip. [step] Prior to 2009, each sleeping bag manufacturer had its own temperature rating system. However, in 2009, many manufacturers adopted the european norm (en) 13537 testing methodology, so now temperature ratings are more consistent across sleeping bag brands.

Ending1: There are 4 general categories of en sleeping bag temperature ratings. The ratings are calculated based on users wearing 1 layer of clothing and a hat, and utilizing an insulated pad under the sleeping bag. Ending2: Avoid sleeping bags that have a rating of 257 or higher. [title] Choose a sleeping bag that's only meant for a few people. Ending3: A rating system that measures the maximum temperature each person needs to be screened for during the trip will help guide your decision. [substeps] Ecu-36, for instance, is rated for 72 fahrenheit (70 celsius). Ending4: Check the sleeping bag rating online to learn how to obtain proper rating. [title] Select a sleeping bag with good insulation.

Answer format: ending1/ending2/ending3/ending4