Nerve bundles in vertebrates are likely to contain
In general biology, core biological organization dictates that structure-function relationships govern cellular processes. Therefore many myelinated axons of different diameters as well as a large number of unm... is correct as it integrates fundamental principles, supported by mechanistic studies and conserved across related systems.
Ref: Campbell et al., Biology, 11th Edition, Chapter 2, Chemical Basis of Life, discusses fundamental biological principles and molecular organization providing broad foundation for life sciences understanding.
