A synonym for seldom is rarely.
A synonym for threadbare is worn.
A synonym for constable is detective.
A synonym for illiterate is ignorant.
That answer would be a Deer
I Have Been Wondering if Bambi was out there too long?
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.