Final answer:
Based on the information provided, the most likely problem for an adult male aged 50 would be an increase volume of blood.
Step-by-step explanation:
Based on the information provided, the most likely problem for an adult male aged 50 would be an increase volume of blood (option C). As individuals age, the volume of blood tends to increase due to factors like weight gain and changes in hormone levels. This can put extra strain on the heart and increase the risk of cardiovascular problems.