#include&lt;stdio.h&gt;   #include&lt;stdlib.h&gt;&nbsp;   int main&#40;&#41;   &#123;       int ret;       int *ptr;       ptr = &#40;int *&#41;malloc&#40;sizeof&#40;int&#41;*10&#41;;       free&#40;ptr&#41;;       free&#40;ptr&#41;;       return 0;   &#125;
A. it will print nothing
B. it will give segmentaion fault
C. undefined behaviour
D. none of the mentioned
Answer:A
#include&lt;stdio.h&gt;   #include&lt;stdlib.h&gt;&nbsp;   int main&#40;&#41;   &#123;       int ret;       int *ptr;       ptr = &#40;int *&#41;malloc&#40;sizeof&#40;int&#41;*10&#41;;       free&#40;ptr&#41;;       free&#40;ptr&#41;;       return 0;   &#125;
A. it will print nothing B. it will give segmentaion fault C. undefined behaviour D. none of the mentioned
Explanation:If the free() has already called before, undefined behaviour occurs.