Answer the following question, with explanation first.
What could cause people who put off having a check up change their ways quickly?\nOptions:\n- pain\n- anxious\n- supposedly good hindsight\n- uncertainty\n- trouble

pain
Pain is a highly unpleasant physical sensation.

When one feels pain, they try to find out the health issue for it.

Check up helps people findout any health issues.

.

Therefore, the answer is pain