#include &lt;iostream&gt;    #include &lt;cstring&gt;    using namespace std;    int main &#40;&#41;    &#123;        char str1&#91;10&#93; = &quot;Hello&quot;;        char str2&#91;10&#93; = &quot;World&quot;;        char str3&#91;10&#93;;        int  len ;        strcpy&#40; str3, str1&#41;;        strcat&#40; str1, str2&#41;        len = strlen&#40;str1&#41;;        cout &lt;&lt; len &lt;&lt; endl;        return 0;    &#125;
A. 5
B. 55
C. 11
D. 10
Answer:A
#include &lt;iostream&gt;    #include &lt;cstring&gt;    using namespace std;    int main &#40;&#41;    &#123;        char str1&#91;10&#93; = &quot;Hello&quot;;        char str2&#91;10&#93; = &quot;World&quot;;        char str3&#91;10&#93;;        int  len ;        strcpy&#40; str3, str1&#41;;        strcat&#40; str1, str2&#41;        len = strlen&#40;str1&#41;;        cout &lt;&lt; len &lt;&lt; endl;        return 0;    &#125;
A. 5 B. 55 C. 11 D. 10
Explanation:In the program, We are concatanating the str1 and str2 and printing