ol.parentheses {
  padding-left: 0;
  margin-left: 2em;
}
ol.parentheses li {
  list-style-type: none;
  counter-increment: cnt;
}

ol.parentheses li::before {
  content: "(" counter(cnt) ") ";
  display:inline-block;
  margin-left:-2em;
  width: 2em;
}
ol ol.parentheses {
  margin: 0 0 .5rem 2rem;
}