How many titles are listed in the dictionary of occupational

Which evidence is most likely used to indicate the beginning of solar system formation? a. materials combined to form a mass. b. materials were pulled together by gravity. c. water condensed and collected to form oceans. d. different species of microorganisms lived on earth.

How would i answer this for an exam?

Why did the united states lead a coalition to invade iraq in 1991? o a. there was a fundamentalist revolution in iraq. o b. iraq had invaded iran. o c. an oil embargo had started in the middle east, o d. iraq had invaded kuwait.