#include &lt;stdio.h&gt;    #include &lt;stdarg.h&gt;    int f&#40;char c, ...&#41;;    int main&#40;&#41;    &#123;        char c = 97, d = 98;        f&#40;c, d&#41;;        return 0;    &#125;    int f&#40;char c, ...&#41;    &#123;        va_list li;        va_start&#40;li, c&#41;;        char d = va_arg&#40;li, char&#41;;        printf&#40;&quot;%c\n&quot;, d&#41;;        va_end&#40;li&#41;;    &#125;
A. Compile time error
B. Undefined behaviour
C. a
D. b
Answer:A
#include &lt;stdio.h&gt;    #include &lt;stdarg.h&gt;    int f&#40;char c, ...&#41;;    int main&#40;&#41;    &#123;        char c = 97, d = 98;        f&#40;c, d&#41;;        return 0;    &#125;    int f&#40;char c, ...&#41;    &#123;        va_list li;        va_start&#40;li, c&#41;;        char d = va_arg&#40;li, char&#41;;        printf&#40;&quot;%c\n&quot;, d&#41;;        va_end&#40;li&#41;;    &#125;
A. Compile time error B. Undefined behaviour C. a D. b