Answer: D

Reasoning: Placing calcium hydroxide inside the pulp chamber after internal bleaching neutralizes residual peroxide, raises the pH and blocks the inflammatory process that triggers external cervical resorption; mixing or dressing with sodium perborate plus Ca(OH)₂ therefore minimizes this complication, whereas alcohol, α-tocopherol, or NaOCl combinations do not show this protective effect in the literature [de Sa et al., 2011, PMID 22186809; Fuss et al., 1989, PMID 2637327].