What is a significant feature of flowers that are in the bloom stage?

Flowers in the bloom stage are characterized by being fully open, which allows for processes such as pollination to occur. At this point, the flower has reached a mature state, making it recognizable and defined by its timing in the lifecycle. Being in bloom means the flower has transitioned from the earlier stages of development—such as budding—to a stage where it actively serves its purpose for reproduction, attracting pollinators with its shape, color, and scent.

In contrast, the other options refer to either the initial stages of flower development or imply inactivity. For instance, flowers that are just beginning to form or are still in the bud stage have not yet reached their functional and visually distinguishable qualities of being fully open and operational. Furthermore, inactive flowers do not serve their reproductive purpose and thus do not represent the vibrant and active phase that blooming signifies.