Final answer:
Grasses are typically the first species to repopulate a habitat after a flood due to their ability to quickly grow and reproduce in poor soil conditions, marking the beginning of ecological succession towards a climax community.
Step-by-step explanation:
The species that would be the first to repopulate a habitat affected by a flood is C. Grasses.
Ecosystems undergo a process of natural recovery after disturbances such as floods, a process known as ecological succession. During the early stages of this process, pioneer species like grasses that can grow and reproduce quickly are typically the first to establish themselves. These plants can colonize the disturbed area rapidly because they are often adapted to thrive in challenging conditions with poor soil quality. They play a crucial role in improving the soil, thus preparing the area for later stages of succession, which may include bushes and trees. Over time, the succession process leads to a more stable and mature ecosystem, often culminating in a climax community, where the species composition remains relatively stable until the next disturbance occurs.