Which are the "s" and "t" prepositions

A. sound, took, take, till

B. since, through, throughout, till

C. thorough, that, test

D. since, sass, tag, tail

We can exclude all the options that have verbs in them (at least one verb)

A "took"

and which have nouns:

C. "test"

D. "tail"

so we are left with the option B. and yes - all the words in this options are prepositions, so it's the correct answer!