Which is the best way to combine the sentences using a semicolon? "the world’s nations must cooperate. one nation cannot solve the world’s problems by itself. " explain with your reasoning.

a. the world’s nations must cooperate; for one nation cannot solve the world’s problems by itself.
b. the world’s nations must cooperate; one nation cannot solve the world’s problems by itself.
c. the world’s nations must cooperate; one nation cannot solve the world’s problems by itself.

Which statement best describes the use of the underlined word in the excerpts? in excerpt 1, it refers to personal growth, while in excerpt 2, it suggests the physical act of moving. in excerpt 1, it refers to personal growth, while in excerpt 2, it suggests scientific discoveries. in excerpt 1, it refers to societal advancement, while in excerpt 2, it suggests the gradual march of time. in excerpt 1, it refers to societal advancement, while in excerpt 2, it suggests steps toward a particular goal.