What is a sequence type in Python?

A sequence type in Python is indeed defined as a data structure that holds an ordered collection of items. This includes built-in types such as lists, tuples, and strings. Sequence types are characterized by their ability to store a collection of items in a specific order, allowing for indexing and iteration through the items.

For instance, in a list, you can access items by their index (e.g., my_list[0] retrieves the first item). This ordered nature allows for predictable retrieval and manipulation of data. Additionally, operations like slicing are available on sequence types, enabling you to obtain sub-portions of the collection effectively.

The other options refer to different concepts within Python. A variable that can change refers to mutable vs. immutable types, a function that returns multiple values is typically handled using tuples or other structures, and a type of conditional statement pertains to control flow, which is unrelated to the concept of sequences. Thus, choice B accurately describes what a sequence type is in Python.