Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to help stop cruelty towards animals [title] Avoid products that are tested on animals. [step] A variety of products, from cosmetics to pharmaceutical drugs, are tested on animals. Animal rights advocates disagree with the use of such products for a variety of reasons.

Ending1: The main reason these products are tested on animals is that they boost their immune system and improve their health. Products that encourage an animal's immune system should be avoided. Ending2: Testing causes painful physical side effects for animals, lab conditions are often cramped and unpleasant, and animals are often killed or die unintentionally during the process. Know what products are likely to be tested on animals and avoid such products. Ending3: However, they can say that they should be avoided after clinical use. Regardless of where the product was tested, animals should not ingest too much of it and should not consume it for fear of infection. Ending4: These products contain very high levels of harmful chemicals. When animal cruelty is the focus of animal rights advocacy, you will want to only use products you think animals would like.

Answer format: ending1/ending2/ending3/ending4