My company is an LTD. What company type do I select in Liquid?

If you have a LTD (limited company), you should select the type Corporation. 

Ltd. is a standard abbreviation for "limited," a corporate structure available in countries including the U.K., Ireland, and Canada. The term appears as a suffix that follows the company name and indicates that it is a private limited company.

In the United States, a limited company is more commonly known as a Corporation (corp.) or with the suffix incorporated (inc.).