Which of the following species are involved

Which of the following species is involved in the mechanism of OH^- substitution of chlorobenzene

When phenol is reacted with CHCI_3 and NaOH followed by acidification, salicylaldehyde is obtained. Which of the following species is/are involved in the above mentioned reaction as intermediate(s)?

Which of the following species exists:

Which of the following complex species involves d^(2)sp^(3) hybridisation?