The difference between a random walk and a submartingale is the expected price change in a random walk is ______ and the expected price change for a submartingale is ______.

The difference between a random walk and a submartingale is the expect

1.	The difference between a random walk and a submartingale is the expected price change in a random walk is ______ and the expected price change for a submartingale is ______.
A.	positive; zero
B.	positive; positive
C.	positive; negative
D.	zero; positive
Answer» E.