It really comes down to what the Bible says.
The Catholic church does not have the corner on the truth.
Sure she does, she is the pillar and foundation of it.
Truth exists elsewhere, but the fullness of truth that God has revealed to man is found within the teachings of the Catholic Church. Vatican 2 stated that in Lumen Gentium.
Regards
In some sense, I would entertain (B)(2). We do not have a corner on Jesus, we think Jesus has a corner on us. But maybe I don't know what you mean by having a corner. It's not that the other groups of professing Christians don't know anything at all. It's not that a two seed in the spirit baptized by fire, foot-washin', snake-handlin', poison drinkin' person is never going to receive the grace to repent and to believe the Gospel or that if he should do so Jesus will ignore him. We're not saying that. God is very generous with ALL of us.
But I do think that those who have preserved that pesky apostolic succession and intend the sacraments as they semper, ubique, et ab omnibus have been intended have what Benedict XVI calls "the means of grace".
I think anyone who witnessed the backing and forthing here on FR about what the Scriptures say would be hard pressed to say that without an authoritative "school", as you might say, of interpretation, the scriptures may be what it all comes down to, but agreement about what they say is hard to come by.
The Bible is indeed the Word of God, but you only know that because the Catholic Church told you so. How do you know what books should be in the Bible when the Bible doesn't tell you? You only know it because the Catholic Church definitively declared the Bible canon at the end of the fourth century.
If the Bible canon is necessary for our salvation, but Christ did not reveal it to His apostles, then Christ must have established an authority that would guarantee the early Christians' determination of the Bible canon after He ascended into heaven. This authority is the Holy Catholic Church.
The Catholic Church wrote, translated, copied, and preserved God's written word throughout the ages. That is the only reason you even have a Bible.