Which revision of the third sentence follows the style guide and best retains the clarity of the original?

we conducted a survey of notaries public in the immediate area and asked which type of notary stamp they liked best. everyone but sara and jonah chose a pre-inked stamp. her preference was an embosser and his was an integrated ink pad.

a. two of the notaries public preferred an embosser and an integrated ink pad.

b. one notary public preferred an embosser and the other an integrated ink pad.

c. their preference was an embosser and an integrated ink pad.

d. she preferred the embosser and he preferred the integrated ink pad.