This program is valid for

#include<stdio.h>
#include<netinet/in.h>
#include<sys/types.h>
#include<sys/socket.h>
 
int main()
{
    int fd_client,fd, len;
    struct sockaddr_in add_server;
    fd_client = socket(AF_INET,SOCK_STREAM,0);
    if (fd_client == -1)
    {
        perror("fd_sock");
        exit(1);
    }
    add_server.sin_family = AF_INET;
    add_server.sin_port = ntohs(4001);
    add_server.sin_addr.s_addr = inet_addr("144.29.8.2");
    len = sizeof(add_server);
    fd  = connect(fd_client,(struct sockaddr*)&add_server,len);
    return 0;
}

A. IPv4

B. IPv6

C. both IPv4 and IPv6

D. none of the mentioned

Answer: Option A