Which three terms are used to describe data at Layers 1, 2, and 4 of the OSI model? (Choose
three.)

A.
PDUs

B.
Bits

C.
Sequences

D.
Segments

E.
Packets

F.
Frames

Explanation:
Bits -1 layer
Frames – 2 layer
Segments – 4 layer
http://en.wikipedia.org/wiki/OSI_model