A 58-year-old man presents with painless bright red bleeding per rectum for 2 months. Anoscopy reveals a bleeding lesion above the pectinate line (marked **A** in the diagram). The lesion is biopsied and shows columnar epithelium with adenocarcinoma. Which of the following lymph node groups would be the FIRST site of metastatic spread for a malignancy arising from the region marked **A**?