Answer: Begin CPR by doing chest compressions
Step-by-step explanation: In a situation where someone collapses and is clutching their chest, it is crucial to act quickly. The first step should be to check their responsiveness and breathing. If the person is unresponsive and not breathing or only gasping, start performing CPR immediately, focusing on chest compressions.
While it's important to get help and an AED as soon as possible, starting CPR right away can help maintain blood flow to the brain and other vital organs, increasing the person's chances of survival. If there were bystanders, you could instruct one of them to call emergency services and another to fetch the AED. However, since you are alone, prioritize starting CPR before leaving to get help or an AED.