#include &lt;stdio.h&gt;    #define SYSTEM 20    int main&#40;&#41;    &#123;        int a = 20;        #if SYSTEM == a        printf&#40;&quot;HELLO &quot;&#41;;        #endif        #if SYSTEM == 20        printf&#40;&quot;WORLD\n&quot;&#41;;        #endif    &#125;
A. HELLO
B. WORLD
C. HELLO WORLD
D. No Output
Answer:A
#include &lt;stdio.h&gt;    #define SYSTEM 20    int main&#40;&#41;    &#123;        int a = 20;        #if SYSTEM == a        printf&#40;&quot;HELLO &quot;&#41;;        #endif        #if SYSTEM == 20        printf&#40;&quot;WORLD\n&quot;&#41;;        #endif    &#125;
A. HELLO B. WORLD C. HELLO WORLD D. No Output