VBA probleme consante requise

Bonjour à tous,

C'est mon travail sur Amercian Option, mais quand je voudrais exécuter la function, la réponse est toujours ¨Constante Requise¨, j'ai l'examen demain, merci pour votre aide !!!

Function CallAm(S0, K, r, rd, sigma, T, n) As Double

Dim epsilon As Double
Dim u As Double, d As Double, a As Double, p As Double, q As Double


epsilon = T / n

u = Exp(sigma * Sqr(epsilon))
d = 1 / u
a = Exp(r * epsilon)
p = (Exp((r - rd) * epsilon) - d) / (u - d)
q = 1 - p

Dim i, j As Integer
Dim tr2(n, n) As Double
Dim tr3(n, n) As Double
Dim ABC As Double

tr2(0, 0) = S0
For j = 1 To n
For i = 0 To (j - 1)
tr2(i, j) = tr2(i, j - 1) * u
Next
tr2(j, j) = tr2(j - 1, j - 1) * d
Next

For i = 0 To n
tr3(i, n) = Application.WorksheetFunction.Max(tr2(i, n) - K, 0)
Next
For j = (n - 1) To 0 Step -1
For i = 0 To j
ABC = Application.WorksheetFunction.Max(tr2(i, j) - K, 0)
tr3(i, j) = (p * tr3(i, j + 1) + q * tr3(i + 1, j + 1)) / a
tr3(i, j) = Application.WorksheetFunction.Max(ABC, tr3(i, j))
Next
Next

CallAm = tr3(0, 0)

End Function