Final answer:
Petroleum jelly (such as Vaseline) is a safe lubricant to apply to cracked lips caused by chemotherapy stomatitis.
Step-by-step explanation:
When it comes to cracked lips caused by chemotherapy stomatitis, a suitable lubricant to consider is petroleum jelly (such as Vaseline).
It creates a protective barrier on the lips, helps retain moisture, and aids in preventing further cracking or chapping.
It's important to note that you should consult with a healthcare professional or your oncologist before using any products on your lips during chemotherapy.