Z-Scores from Frozen Mu and Sigma

The frozen σ is 0.030 and m = 0. A test bar's spread is −0.066. What is z?

• −0.66
• −2.2
• −0.45

Which of these is look-ahead?

• A σ frozen from the training window
• A σ from a trailing window that ends at bar t
• A σ from a window centred on bar t