Read the sentence. The tour guide _____ that either candles or a lantern _____ used to see into the tomb. Which verbs agree with the subjects in the sentence? explains, are explain, is explain, are explains, is
I am not sure I understand your multiple choices for answers, but the correct words to put into your sentence are: 'explains', and 'is'. Because the word 'either' has been used, that changes the the word after lantern from multiple to singular.