The best response based on the scenario provided would be:
C Certhidia oliveacea; its tiny pointed bill is the best adapted to sip nectar.
Explanation: In this scenario, the newly formed island is covered with cacti that have honey-filled flowers. A finch species with a tiny pointed bill would likely be most successful in accessing the nectar from the flowers, which would provide them with a crucial food source. The other options either focus on traits that are less relevant to the environment (e.g., large size or bill adaptations for digging worms) or general statements about intermediate traits that may not be as directly advantageous in this specific context.