Here the earliest text (the printer’s manuscript) reads ezrum; the original manuscript is not extant for this word. There is one other occurrence of ezrum in the text:
𝓞 is not extant for this instance either.
As explained in the discussion under Alma 10:31, the name Zeezrom is misspelled in 𝓞 as Zeezrum for every extant occurrence of the name in Alma 11 (six times, from verses 21 through 35). All of these instances of Zeezrum occur after Alma 11:12 (that is, after both occurrences of ezrum), which suggests that in 𝓞 the misspelling Zeezrum was influenced by the spelling ezrum. On the other hand, the 1830 compositor twice set ezrum as ezrom, apparently under the influence of the first occurrence of the name Zeezrom (in Alma 10:31), the only instance of Zeezrom that preceded the word ezrum. The critical text will restore the spelling ezrum, the reading of the earliest extant source, the printer’s manuscript.
Summary: In accord with the reading of the printer’s manuscript (and the probable reading of the original manuscript), restore ezrum as the name of the monetary unit.