The following is$/$are true about Recursive Functions:

$1)$ Recursion is a technique based on the divide and conquer principle. That principle calls for us to define the solution of a bigger problem in terms of the solution of a smaller version of itself.

$2)$ A recursive function is a function that calls itself.

$3)$ Recursive functions can have one or more base cases$/$steps and one or more recursive cases$/$steps$\mathrm{.}4)$ All the above