Question

multiple-choice question
what makes this a function?
its straightish.
for each time, there is only one temperature recorded.
it has a horizontal section.
rewatch

Explanation:

A function is defined as a relation where each input (in this case, time) has exactly one output (temperature). The option "It's straightish" is not a valid mathematical definition of a function. The option "For each time, there is only one temperature recorded" fits the definition of a function as each input (time) has a unique output (temperature).

Answer:

B. For each time, there is only one temperature recorded.