Choosing a math class U.S Undergrad seeking advice

[Zhan Zhang]

I am gonna to be a senior in math for fall 2014 and intend to apply for master programs in financial engineering and pursue a career in this field. I still want to sign up for one class but I got several to choose from:
1. Numerical Analysis;
2. Derivative pricing(I used to be a finance major and took similar but easier class before);
3. Nonlinear Programming;
4. Time series analysis;

I am not quite sure about specifically what I am going to do in the future, but maybe derivatives.

Any advice?

Thanks!