In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".

[header] How to care for a midnight blue rose bush [title] Pick out midnight blue roses that look healthy. [step] Strong, healthy plants will be more resistant to diseases of all kinds, so the fight against rose disease starts at planting time. Select healthy rose plants that have sturdy-looking leaves and stems and don't show any signs of disease or pests. <sep> (A) [substeps] Check for signs of disease by checking the flowers themselves. Circles of green or blue lines with cross bones are signs of disease. (B) [substeps] Look to see if any of the leaves have black spots, red leaves, or chew marks. These are all signs of disease or infestation. (C) [substeps] Use a hand or wire brush to gently brush rose petals, leaves, and stems. You can also spray bright, wet leaves with a variety of laundry detergent. (D) [substeps] You can buy dawn roses, which grow well in early spring, if you want snow roses. They also grow best in warm, sandy areas.
B