When studying hybridization over time,researchers have found that

A)when reinforcement occurs, the production of hybrid individuals continues because hybridization is favoured or reinforced.
B)when stability occurs, barriers to reproduction are strong, and hybrid numbers decline.
C)hybridization between polar bears and grizzly bears is one of reinforcement.
D)when fusion occurs, there is a weakening of reproductive barriers, gene flow continues, and the two hybridizing species become increasingly more alike.