To reconstruct how medieval texts circulated, scholars often focus on unusual shared errors, since ordinary wording may arise independently. A manuscript of a poem called Alder, dated 1420–1430, omits a word in line 84, disrupting the poem’s meter. A second hand later added a six-line stanza in Alder’s margin; ink analysis dates the addition to no later than 1435. A manuscript called Briar, dated 1450–1460, has the same omission and incorporates the stanza into its main text, preserving an unusual misspelling and line break found in Alder’s marginal addition. A third manuscript, Cedar, dated 1430–1440, has neither the omission nor the stanza. No other copies from the period survive, and records do not show where Alder or Briar was kept before 1500. Taken together, the evidence suggests that ______
Which choice most logically completes the text?