Multiple anterior rootlets arise from the spinal cord and merge to form a single root, which contains axons only. These axons arise from cell bodies in the anterior and horns of the spinal cord. Posterior rootlets arise from a single root, which contains axons only. The cell bodies of these neurons are located in a , which is within the posterior root. Each anterior root and its corresponding posterior root unite within the to become a spinal nerve.

Explanation:

Multiple anterior rootlets arise from the spinal cord and merge to form a single anterior root. which contains Anterior roots contain motor axons only.

These axons arise from cell bodies in the anterior and lateral horns of the spinal cord.

Posterior rootlets arise from a single posterior root,which contains sensory axons only.

The cell bodies of these neurons are located in a posterior root ganglion , which is within the posterior root. Each anterior root and its corresponding posterior root unite within the intervertebral foramen to become a spinal nerve.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.

well, i believe that the answer is 2. : 3