Here, Paul admits he has not attained perfection, and in vs. 9 he even says that this includes not having yet achieved "the righteousness which comes from God on the basis of faith." This presents us with a conundrum, because Paul is generally thought to teach that faith in Christ's death and resurrection is sufficient to attain salvation through grace (Ephesians 2:8). In terms of context we should consider something from the letter's previous chapter:
So then, my beloved, just as you have always obeyed, not as in my presence only, but now much more in my absence, work out your salvation with fear and trembling; for it is God who is at work in you, both to will and to work for His good pleasure. (2:12-13)
This sheds light on what Paul means in chapter 3. He is "working out his salvation," admitting that he has not attained perfection. He adopts a humble attitude of "fear and trembling," even as he maintains his confidence that his faith in Christ's atoning death will see him through "in order that I may attain to the resurrection from the dead." (v. 11)
These chapters present a powerful insight into Paul's soteriology as applied in his personal spiritual quest. In terms of the multiple choices given in the OP, perhaps number 4 comes the closest. My own formulation would be "Paul is on the path of salvation but admits he is not perfect yet, and therefore see his course as a work in progress."