Final answer:
A function that assigns each value of the domain to more than one value of the range is referred to as a many-to-one function.
Step-by-step explanation:
The function mentioned in the question that assigns each value of the independent variable (domain) to more than one value of the dependent variable (range) is called a many-to-one function. This is because each value of the domain (independent variable) corresponds to just one value in the range, but multiple values in the domain can correspond to the same value in the range.
The other options given are: a) One-to-one, which would have a one-to-one correspondence between the domain and range; b) Onto, which implies every value in the range is mapped to by the domain; and d) Bounded, which is a term used to describe a function whose values do not exceed certain limits.