What Is the Difference Between Concurrent-Measures Designs and Repeated-Measures Designs

What is the difference between concurrent-measures designs and repeated-measures designs?

A) Concurrent-measures design is an independent-groups design; repeated-measures design is a within-group design.
B) Concurrent-measures designs expose participants to the levels of the independent variable at roughly the same time; repeated-measures designs expose participants to the levels of the independent variable sequentially.
C) Concurrent-measures designs can have any number of levels of an independent variable; repeated-measures designs can only have two levels of the independent variable.
D) There is no difference; they are two terms for the same design.