Which of the following best illustrates a pair of sentences that are joined by an understood relationship?
a. it rained for ten days and ten nights. grandmother grady called a company to drill a well.
b. i don't understand a word you said. have you taken a course in english literature?
c. detective smiley scanned the dim hallway. he pulled his pistol from its holster.
d. luke put three dollars into the office football pool. he was looking forward to vacation.

C. Detective Smiley scanned the dim hallway. He pulled his pistol from its holster.

Among all the sentences in the choices, this sentence best illustrates a pair of sentence that are joined by an understood relationship. If we analyze the sentences, the first sentence states that Smiley is a detective who just scanned the dim hallway. Dim hallways usually mean that there might be danger ahead therefore in the second sentence; the detective took out his gun from its holster. It is not written specifically but the sentences have this connotation.