“Awful, insulting,” Mr. Mulryan said last week. “How would any of those doing the report like it if one of their siblings was being treated like that?”

The scandal began when Catherine Corless, an amateur historian, dug into the history of the old mother-and-baby home in Tuam that was managed by the Sisters of Bon Secours from 1925 to 1961. It was one of more than a dozen homes throughout Ireland that were often run by Catholic religious orders, but were funded and supposedly regulated by the government.

Ms. Corless came across the death certificates for nearly 800 children who had died at the home, often of contagious disease. But there were virtually no burial records, an absence in the public record that neither the Bon Secours nor the local government could explain.

After further sleuthing, she wrote an article in the local journal in 2012 that strongly suggested that the remains of hundreds of children, all born to unwed mothers and all baptized in the Catholic faith, had not been buried in consecrated ground, but in parts of a disused septic system dating to when the home was a 19th-century workhouse.

Those suspicions were confirmed last March by forensic investigators working for the Commission of Investigation Into Mother and Baby Homes, which had been established by the chastened government in response to Ms. Corless’s work. The commission is charged with examining the social and historical reasons for these institutions, to which Irish society had long relegated vulnerable, unwed mothers and their children.

Ms. Zappone, meanwhile, dispatched a panel of technical experts who eventually developed the five options. They reported that the considerable complications included the amount of juvenile remains and their commingling, which would make individual identifications difficult, and the potentially limited yield of DNA tests. The experts emphasized the importance of communicating “realistic expectations,” given the need to match extracted samples with those of living relatives and the likelihood that samples taken from infants would be of poor quality.