#include &lt;iostream&gt;    #include &lt;fstream&gt;    using namespace std;    int main &#40;&#41;    &#123;        char ch;        streambuf * p;        ofstream os &#40;&quot;test.txt&quot;&#41;;        pbuf = os.rdbuf&#40;&#41;;        do &#123;            ch = cin.get&#40;&#41;;            p -&gt; sputc&#40;ch&#41;;        &#125; while &#40;ch != '.'&#41;;        os.close&#40;&#41;;        return 0;    &#125;
A. dot operator
B. insertion operator
C. $ symbol
D. None of the mentioned
Answer:A
#include &lt;iostream&gt;    #include &lt;fstream&gt;    using namespace std;    int main &#40;&#41;    &#123;        char ch;        streambuf * p;        ofstream os &#40;&quot;test.txt&quot;&#41;;        pbuf = os.rdbuf&#40;&#41;;        do &#123;            ch = cin.get&#40;&#41;;            p -&gt; sputc&#40;ch&#41;;        &#125; while &#40;ch != '.'&#41;;        os.close&#40;&#41;;        return 0;    &#125;
A. dot operator B. insertion operator C. $ symbol D. None of the mentioned
Explanation:This program will stop getting the input, When it occurs the dot(.) operator.