The commonest lymph node to enlarge in acute tonsillitis is:

(b) Jugulo-digastric lymph node(Ref. Scott Brown, 8th ed., Vol 3; 742)Lymphatic drainage of tonsil is to jugulo-digastric lymph node (upper deep cervical lymph node). The most common cause of enlargement of these lymph nodes is the tonsillar infection because of which they are also known as tonsillar nodes.Jugulo-omohyoid lymph nodes (middle deep cervical lymph nodes) are known as lymph nodes of tongue as the lymphatics from all over the tongue ultimately drain here.