The reason why it wouldn't be practical for big corporations to build a network with only one (1) transmission medium is: C. because they require a combination of transmission media types to function properly.
A big corporation can be defined as a corporate organization that has facilities and owns (controls) assets that are used for the manufacturing of goods and services in at least one (1) country, other than its headquarter (home office) located in its home country.
This ultimately implies that, a big corporation is a corporate organization that owns (controls) its business operations in two or more countries.
In light of the above, a big corporation require a combination of multiple transmission medium or transmission media types such as the following, in order for them to function properly, effectively, and efficiently:
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