Final answer:
Siena should plant the roses at coordinates (–2, 4).
Step-by-step explanation:
To determine where Siena should plant the roses, we need to consider their distance from the marigolds and lavender. The roses should be planted 6 feet away from the marigolds and 5 feet away from the lavender. Looking at the given options, the coordinates (–2, 3) and (–3, 2) are 6 feet away from the marigolds, but only the coordinates (–2, 4) are 5 feet away from the lavender. Therefore, Siena should plant the roses at coordinates (–2, 4).