Untitled

<!DOCTYPE html>
<html>
<head>
<style>

 .correcto::before {
  content: "\25B7";
}

.incorrecto::before {
  content: "\26CC";
}

.seleccion::before {
  content: "\2754";
}

.a::before {
  content: "A";
}

.b::before {
  content: "B";
}

.c::before {
  content: "C";
}

.d::before {
  content: "D";
}
</style>
</head>
<body>
<span class="correcto"></span><br>
<span class="incorrecto"></span><br>
<span class="seleccion"></span><br>
<span class="a"></span><br>
<span class="b"></span><br>
<span class="c"></span><br>
<span class="d"></span><br>

</body>
</html>