Which polynomial is in standard form?
A) 4x2 + 5x3 + 4x5 − 6x
B) 6x3 + 5x5 − 4x2 − 2x4
C) 7x + 2x2 + 5x3 + 4x5
D) 8x5 + 6x4 − 4x3 − 3x2