Unlike gradualism, punctuated equilibrium involves
a. a slow change in evolution over time.
b. stable periods of change interrupted by rapidly occurring change.
c. species that are said to be in equilibrium.
d. a steady change in evolution over time.

The correct answer is option b. stable periods of change interrupted by rapidly occurring change.

The punctuated equilibrium is referred to a evolutionary pattern, in which the organism changes rapidly in order to survive the changing environment and remain unchanged for a very long period of time. hence, in this case, a stable period of change is followed by a rapidly changing phase.

The gradualism refers to the slow and steady changes, which helps the organism to adapt the changing environment.