#include&lt;stdio.h&gt;   #include&lt;fcntl.h&gt;   #include&lt;sys/stat.h&gt;   #include&lt;sys/mman.h&gt;&nbsp;   int main&#40;&#41;   &#123;       int s_id;       s_id = shm_open&#40;&quot;shared_mem&quot;,O_CREAT|O_RDWR,0666&#41;;       printf&#40;&quot;%d\n&quot;,s_id&#41;;       if&#40;shm_unlink&#40;&quot;shared_mem&quot;&#41; == -1&#41;           perror&#40;&quot;shm_unlink&quot;&#41;;       return 0;   &#125;
A. -1
B. 1
C. 2
D. 3
Answer:A
#include&lt;stdio.h&gt;   #include&lt;fcntl.h&gt;   #include&lt;sys/stat.h&gt;   #include&lt;sys/mman.h&gt;&nbsp;   int main&#40;&#41;   &#123;       int s_id;       s_id = shm_open&#40;&quot;shared_mem&quot;,O_CREAT|O_RDWR,0666&#41;;       printf&#40;&quot;%d\n&quot;,s_id&#41;;       if&#40;shm_unlink&#40;&quot;shared_mem&quot;&#41; == -1&#41;           perror&#40;&quot;shm_unlink&quot;&#41;;       return 0;   &#125;
A. -1 B. 1 C. 2 D. 3
Explanation:On success the shm_open() returns a nonnegative file descriptor.