Final answer:
Increased blood volume would lead to higher blood pressure due to more fluid exerting greater force against the inner walls of the vessels within the circulatory system.
Step-by-step explanation:
The increase of blood pressure can occur through various physiological changes. Among the options provided:
- Increased blood volume will lead to higher blood pressure because there is more fluid within the confines of the circulatory system, creating greater pressure against vessel walls.
- Decreased blood viscosity would actually usually be associated with decreased blood pressure, as thicker blood requires more force to move it through the vessels.
- Decrease in cardiac output means the heart is pumping less blood through the circulatory system, leading to lower blood pressure.
- Increased vessel radius, in the case of arterioles, can lead to a reduction in resistance and thus a lowering of blood pressure.
Therefore, the change that will result in increased blood pressure is 'increased blood volume'.