Here scribe 2 of 𝓟 wrote throght, which could be interpreted either as through (with the t automatically but accidentally added because of the orthographically similar word thought) or as a shortened version of throughout. Oliver Cowdery corrected throght to throughout, apparently when he proofed 𝓟 against 𝓞.
As discussed under Mosiah 29:1, the text can have either through or throughout in the context of “the land”, although throughout is the expected form. In this part of the text, throughout is the form consistently used to refer to the extent of Alma’s preaching:
Thus the critical text will accept Oliver’s correction of throght to throughout, the probable reading in 𝓞.
Summary: Accept in Alma 5:1 throughout, Oliver Cowdery’s correction in 𝓟 and the probable reading in 𝓞, no longer extant here.