#include &lt;stdio.h&gt;    int main&#40;&#41;    &#123;        char buf&#91;12&#93;;        stderr = stdin;        fscanf&#40;stderr, &quot;%s&quot;, buf&#41;;        printf&#40;&quot;%s\n&quot;, buf&#41;;    &#125;
A. Compilation error
B. Undefined behaviour
C. Whatever user types
D. None of the mentioned
Answer:A
#include &lt;stdio.h&gt;    int main&#40;&#41;    &#123;        char buf&#91;12&#93;;        stderr = stdin;        fscanf&#40;stderr, &quot;%s&quot;, buf&#41;;        printf&#40;&quot;%s\n&quot;, buf&#41;;    &#125;
A. Compilation error B. Undefined behaviour C. Whatever user types D. None of the mentioned