Which of the following sentences contains an independent and dependent clause? a. the boy likes cookies; the girl likes ice cream. b. once i went hiking with my best friend. c. billy jo thinks that the sky is blue because the sun paints it each morning. d. while dreaming, the dog chased a cat down the alleyway to the garbage dump.

Hi !

Your answer should be D

A and B
the two of them are independent clause.
A is two independent clauses joined by a punctuation, a semicolon

B is an independent clause : only one verb "went" (hiking does count as a verb)

C has three verbs. two dependent clauses and " Billy Jo thinks" is a  dependent clause (I think)
Billy Jo thinks //that the sky is blue // because the sun paints it each morning
  ind. cl                        dependent clause               dependent clause

D While dreaming // the dog chased a cat down the alleyway to the garbage
  independent clause ///      dependent clause
dump

so your answer should be D = one dependent clause and one independent clause !!

hope I helped !