What is the output of the following program when the method is called with 4?

void unknown (int n)

{

if (n>0)

unkown (n-1);

System. out. print ("?");

}

A. None of the other answers

B.?

C.?

D.?

C.?

Explanation:

Given code:

void unknown (int n)

{

if (n>0)

unkown (n-1);

System. out. print ("?");

}

Calling code: unknown (4)

This is a recursive invocation of unknown function and causes? to be printed 5 times once each for following values of n.

unknown invocation with n=4 unknown invocation with n=3 unknown invocation with n=2 unknown invocation with n=1 unknown invocation with n=0

When n becomes 0, termination condition is reached and the function returns.

So the output is?