In an efficient market, $\_\_\_\_\_\_\_\_\_\_.$

Question $1$ options:

a$)$

security prices react immediately to new information.

b$)$

security prices are usually far above or below their justified levels.

c$)$

security analysis will enable investors to realize superior returns consistently.

d$)$

security returns can be predicted with various stock characteristics such as size and book$-$to$-$market ratio.