Please choose the correct ending to complete the given sentence: Health: [header] How to improve mental hygiene [title] Challenge negative thought patterns. [step] The way you perceive the situations that happen in your life can greatly determine your mood and outlook. Thinking about your problems over and over without actually coming up with a solution is called rumination.

Ending1: This process can promote feelings of depression and even lead to cardiovascular disease. [substeps] Challenge your negative thought patterns by questioning the validity or certainty of your thought. Ending2: This is when people continually try to imagine that they are the same person twice. When this happens, think more positively and avoid dwelling on negative thought patterns. Ending3: It can be a powerful tool to improve mental hygiene. To help with rumination, try to come up with a scheme for attacking negative thought patterns. Ending4: So, instead of jumping straight into the role of " negative thinker, " challenge yourself by fully addressing the perception that negative thoughts can be okay. [substeps] Don't forget to keep track of the types of thoughts you have.

Answer format: ending1/ending2/ending3/ending4