Which is most likely caused by this type of mutation?

The symptom that is most likely caused by a mutation is "decreased ability to carry oxygen."

This is often associated with mutations in genes that encode for hemoglobin or related proteins in red blood cells. For example, mutations leading to conditions like sickle cell anemia or thalassemia can significantly affect the blood's ability to transport oxygen efficiently.

The other options, while they can be associated with mutations, are less directly linked to a specific type of mutation compared to the effects on oxygen transport. Inability to break down sugar could relate to metabolic disorders (like diabetes) but not necessarily genetic mutations alone; development of cancerous tumors is typically associated with mutations in oncogenes or tumor suppressor genes; and bacterial infections are usually related to immune system function rather than direct mutations affecting oxygen transport.