If your conditional expressions are exclusive which means only one condition can be true then you need to use
else
statements with the
if
s. That would look like this :
#include <stdio.h>
int main() {
int a , b , c ,d ;
scanf("%d %d %d %d" , &a ,&b , &c , &d);
if( ( a == 1 ) || ( a == 3 ) || ( a == 5 ) )
printf("American masculine citizen");
else if( ( b == 2 ) || ( b == 4 ) || ( b == 6 ) )
printf("American feminine citizen");
else if (c==7)
printf("Foreign masculine citizen");
else if (d==8) printf("Foreign feminine citizen");
else
printf("Invalid value");
return 0;
}