Final answer:
The hyphens should be added in a. The well-loved teacher, c. to listen, and d. to her students.
Step-by-step explanation:
The correct answers are a. The well-loved teacher, c. to listen, and d. to her students. Hyphens should be added in compound adjectives and compound nouns. In this sentence, 'well-loved' is a compound adjective modifying the noun 'teacher', so a hyphen should be added between 'well' and 'loved'. 'To listen' and 'to her students' are both infinitive phrases, but since the verb 'listen' is being modified by the adverb 'how', a hyphen should be added between 'how' and 'to'.
Learn more about Hyphens in compound adjectives and infinitive phrases