I765 part 1 question 1

[chelavnzuo]

I'm currently working in the US on TN1 work visa and applying for family-based green card.
For I765 part 1 question 1, should I select box 1.a. Initial permission to accept employment, or 1.c. Renewal of my permission to accept employment?

The reason I'm asking is that I'm not sure if my current TN1 work visa is considered as an existing employment authorization document.

Thanks

[newacct]

Initial permission