@SeaStar11201 You’re applying now, right?
First of all, as I mentioned earlier, taking Calc II in the Spring is essentially pointless, as you applied for Fall 2016 admission (right?), and they will not take your Spring grades into account whatsoever. Spring grades come out approx. a month or so after admission decisions come out.
It won’t look better at all to get a P. If you’re shooting for a P in Calc II, there’s not much of a point in taking it.
However, if you took it for a letter grade and wrote in the additional comments explaining that getting a C in Calc I was not up to your usual standards, and you plan to take Calc II for a letter grade to redeem yourself personally, then that MIGHT reflect well upon you. It could show that you are able to learn from your mistakes, that you want to step outside of your comfort zone, that you want to challenge yourself.
I suppose you could omit the part about the letter grade and just take it P/NP. I don’t think they have any problem with taking P/NP grades in the Spring. It would sort of reflect negatively upon you for grad schools, though, but it’s not the biggest deal in the world. I wouldn’t P/NP it, but that’s my opinion.
If you would like to take the class, then do it for your own benefit - there is a strong possibility that taking Calc II will not increase your chances in the slightest. Furthermore, If you get less than a B in Calc II (or a NP), any admission letters may be rescinded, which you definitely want to avoid.
You probably won’t gain much by taking it, and it could possibly jeopardize your admissions.