The aim of the question is to find the correctly punctuated sentence. Let us use the meaning of each punctuation used in four options.
Option D is correct because a semicolon should only be used to separate two parts of a sentence that could each stand as independent main clauses on their own.Here on either side of semicolon stands independent sentences.
Option A is wrong since it uses comma which is normally used to separate items or clauses. It is used always after a dependent clause that starts a sentence.Here both can be independent clauses.
Option B is wrong since it uses a word ‘cant’ in the place of can’t(cannot). Both are pronounced in the same way, but meanings are different.Cant has several meanings like pious talk,speech delivered in sing song manner,slope and so on which are irrelevant in this sentence.
Option C is wrong because it uses a colon. Colon can only be used to join two main clauses with a noun and no noun is present in this context.