Answer:
When Telemachus respond to Antinous's reply in the assembly, He insists his father is alive, and therefore he cannot condemn his mother for not remarrying
Step-by-step explanation:
When all the suitor start demanding Penelope to get married with another man, since all of them claim that Odysseus is obviously dead if he has not come back after 20 years, Telemachus calls the assembly and communicates that he will go and look for news of his father and only if he can not find any sign that he's alive he would ask his mother to remarry with one of the suitors, since he still believes his father is alive and then his mother would not be free to remarry.