#include &lt;stdio.h&gt;    #include &lt;ctype.h&gt;    int main &#40;&#41;    &#123;        int i;        char str&#91;&#93; = &quot;jobs...&quot;;        i = 0;        while &#40; isalnum&#40;str&#91;i&#93; &#41;&#41;             i++;        printf &#40;&quot; %d\n&quot;,i&#41;;        return 0;    &#125;
A. 1
B. 2
C. 3
D. 4
Answer:A
#include &lt;stdio.h&gt;    #include &lt;ctype.h&gt;    int main &#40;&#41;    &#123;        int i;        char str&#91;&#93; = &quot;jobs...&quot;;        i = 0;        while &#40; isalnum&#40;str&#91;i&#93; &#41;&#41;             i++;        printf &#40;&quot; %d\n&quot;,i&#41;;        return 0;    &#125;
A. 1 B. 2 C. 3 D. 4
Explanation:In this program, We are counting the number of alphanumeric values by using the function isalnum.