Q:

Styles often occur in the same combination: Creating a single class or combining elements?

In one of my recent projects, I noticed that certain styles occur in the same combination repeatedly. According to the DRY principle, I should combine these styles. Regarding a good CSS style, what option is better/the best?
Option 1
Creating a class that contains these styles and simply add it in the HTML to the according elements.
Example
In the HTML:
<a href='#' class="myClass">Link</a>

or
<ul class="myClass">
  <li>Item</li>
<ul>

In the CSS:
.myClass {
  font-weight: bold;
  font-size: 14px;
  color: grey;
}

Option 2
Simply combining all elements that need that style in my CSS, like in the following example.
a,
ul {
  font-weight: bold;
  font-size: 14px;
  color: grey;
}

A:

.myClass {
  font-weight: bold;
  font-size: 14px;
  color: grey;
}

is best ... 
.myclass {
  font-weight: bold;
  font-size: 14px;
  color: grey;
}

is even better (lower-case)
This way, the DOM engine will get to the element without having to stack across all a and all ul tags in your document.

