It mostly depends on WHAT information you want to get out:
Option 1 will not, I think, give you a sensible number; it compares calls logged in a period with an amount of calls breached within that same period. Please note that some of these breached calls might have been logged before the period. The percentage generated would imply, but is not, the percentage of calls meeting their SLA logged within the period.
Option 2 is where my vote would go for %breach (one is comparing resolved calls).
Alternatively, one can report on percentage of breached calls currently open.
One can also report on: out of the amount of calls logged within this period, how many have breached (and transform it into a percentage). Please note that calls could still be open and (about to) breach.
OR: out of the amount of calls logged within this period, how many of the resolved calls have breached. Needless to say, this percentage will vary over time as more calls from that period get closed.
The other thing to keep in mind is the various SLAs. Tallying P1's and P3's in the same heap might give a very skewed picture: eg 99% meeting of SLA could hide 100% missing of P1's
Anyhow, I hope I have given you some food for thought.