Answer: The answer is 1 and 3.
Step-by-step explanation: We are to select the correct options about the number of real roots of a cubic function.
We know that there are three roots of a cubic function, out of which one must be real because the least number of real roots of an odd degree function is 1.
Also, if the second root is real, then the third one must also be real because the complex roots of a function occur in pairs.
Therefore, there is one real root or three real roots for a cubic function.
Thus, the answer is 1 and 3.
