I am eligible for an he healthcare exemption C: "as a dual-status alien who elects to file a joint return with a U.S. spouse." I don't see it as an option in Turbotax

If you file a dual status tax return, you cannot use the standard deduction in TurboTax and you cannnot file married filing jointly.  Please let me know if you have questions.

TurboTax does not list the the first year exemptions under Health Insurance. You will need to choose the option: I'll pick who had it and which months. 

According to the instructions for Form 8965 under types of exemptions, page 3, the type of exemption is Code c, the same code that is used for the option in TurboTax  for Spent 330 days or more outside the US.  So you will need to check this option to receive the exemption.

https://www.irs.gov/pub/irs-pdf/i8965.pdf