Answer:
Contracted blood vessels
Explanation:
The volume of blood is reduced as the vessels are more narrow due to the contraction, so less blood reaches the respiring tissues, causing the force of blood flow to increase as there is less space for normal blood flow to occur. This means that blood pressure increases.
A, plant growth would decrease. Decomposers break down organic materials into nutrients and return these nutrients to the soil. The nutrients are vital to plant growth. If decomposers went extinct, then eventually plants would use up all the existing nutrients and start to die.