A dependent cannot possibly be Head of Household. If you are filing Single or Head of Household then you are claiming your own personal exemption. When you are asked the question about whether you can be claimed as someone else's dependent, your answer is NO, and then you have "claimed" yourself.
Am I Head of Household?
If you qualify as Head of Household, when you enter your filing status (single or married filing separately) into Personal Info, and then enter your qualifying dependent, TurboTax will offer HOH as your filing status.