#include&lt;stdio.h&gt;    #include&lt;fcntl.h&gt;&nbsp;    int main&#40;&#41;    &#123;        int fd, fd2, ret;        fd = open&#40;&quot;san.c&quot;,O_RDONLY&#41;;        ret = close&#40;fd2&#41;;        printf&#40;&quot;%d\n&quot;,ret&#41;;    &#125;
A. 0
B. 1
C. -1
D. none of the mentioned
Answer:A
#include&lt;stdio.h&gt;    #include&lt;fcntl.h&gt;&nbsp;    int main&#40;&#41;    &#123;        int fd, fd2, ret;        fd = open&#40;&quot;san.c&quot;,O_RDONLY&#41;;        ret = close&#40;fd2&#41;;        printf&#40;&quot;%d\n&quot;,ret&#41;;    &#125;
A. 0 B. 1 C. -1 D. none of the mentioned
Explanation:The “close” system call closes a file descriptor but in the program “fd2” in not a file descriptor. Hence close system call returns -1.