In the first half of the twentieth century, many american writers turned their attention to

a) dangerous people and the challenges facing societies that must deal with them
b) extraordinary people and the challenges of society's elite
c)ordinary people and the challenges of everyday life
d)highly educated people and the challenges of the life of the mind

The right answer is  A)dangerous people and the challenges facing societies that must deal with them

The explanation for this is made with the observation of the theme of the literary works of that time, how, social, political and cultural aspects would guide in a decisive way the work of the exponents of that period. Events like the use of the modern war machine in the service of barbarism, the witch-hunt captained by Senator McCarthy, the humiliating defeat in Vietnam culminated in a prose marked by fear, anguish and alienation, represented in the work of authors such as Saul Bellow, Philip Roth and Joseph Heller.

21 balloons is the story of professor william sherman's travels.

in 1883, he set off from san francisco for a balloon ride over the pacific and was found a month later floating with 21 balloons in the atlantic ocean. this seemed an astounding feat and everyone wanted to know what had happened.    

professor sherman was loyal, however, and said he would tell his tale first to the western american explorers club in san francisco, of which he was a member. this built up suspense for several chapters before he began to tell of the wonders of his adventures and the amazing island of krakatoa, an island which had just been blown up by a volcano.  

the residents of krakatoa are all millionaires who live under a "gourmet government" of their own devising. we get to see all the incredible adventures that creative people with unlimited resources would create according to the author.