Sentence Correction

Isotopes in the recently excavated bones of a 14-year-old girl from the Jamestown archaeological site indicate she had eaten a high-protein diet, so was probably the daughter of a gentleman, not a maidservant.

A)she had eaten a high-protein diet, so was probably the daughter of a gentleman, not a maidservant.

B)that she ate a high protein diet, so probably had been the daughter of a gentleman, and not a maidservant.

C)that she had eaten a high protein diet, so was probably the daughter of a gentleman, and not a maidservant's.

D)she ate a high-protein diet, so was probably the daughter of a gentleman, and had not been a maidservant.

E)she had eaten a high-protein diet, thereby had probably been the daughter of a gentleman, not a maidservant's.

Sorce: Veritas Question Bank

I am confused with the OA provided .Could someone from Expert community help me ?

OA
A

IMO A
daughter of a X,not a Y- correct idiom and only A have this format.
A)she had eaten a high-protein diet, so was probably the daughter of a gentleman, not a maidservant.-correct

B)that she ate a high protein diet, so probably had been the daughter of a gentleman, and not a maidservant.

C)that she had eaten a high protein diet, so was probably the daughter of a gentleman, and not a maidservant's. - gives a wrong meaning; not correct usage

D)she ate a high-protein diet, so was probably the daughter of a gentleman, and had not been a maidservant.

E)she had eaten a high-protein diet, thereby had probably been the daughter of a gentleman, not a maidservant's

[spoiler]{A}?[/spoiler]