The world's deepest known trench has never been explored.
a. true
b. false

I would say false. The Mariana Trench, earth's deepest trench, has been explored, but only partially

Answerrecharge zone;

The shia sect of islam is primarily different from sunni islam in the belief that the first legitimate imam following muhammad was imam ali. unlike the three caliphs that succeeded muhammad, ali was part of muhammad's clan (related to him). major shia caliphates include the fatimid and safavid caliphates.  the answer will be option c. shia read more on