Your road to recovery is likely long.                , you have the best healthcare service available right now. A. Saying that B. Having said C. That said D. To say that

C. That said

"That said" is commonly used to introduce a statement that contrasts with or in some way qualifies what was just mentioned. In this context, the sentence suggests that although the process of recovery may be lengthy, there is a positive aspect, which is the availability of excellent healthcare services.

Using "That said" effectively conveys this contrast. The other options do not fit as well:

A. "Saying that" does not convey a similar meaning and is grammatically awkward in this context.
B. "Having said" suggests that the speaker has completed a statement but does not lead into the contrasting information smoothly.
D. "To say that" is not appropriate because it implies a hypothetical statement rather than presenting a real contrast.

Therefore, "That said" is the most suitable choice to express this idea.